How to Report Measurement Uncertainty in Test Reports: A Template and Examples

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-27

Quick Answer

• Report measurement uncertainty as an expanded uncertainty with a coverage factor and confidence level, such as "12.5 ng/mL ± 1.8 ng/mL (k = 2, approximately 95% confidence)."
• Include uncertainty statements when results approach clinical decision limits, when users request them, or when your laboratory's quality system requires them for specific analytes.
• A measurement result without uncertainty information is incomplete for interpretation, but reporting uncertainty does not replace the need for validated methods and ongoing quality control.

At a Glance

Purpose of Uncertainty Reporting in Laboratory Reports

Measurement uncertainty is a quantitative expression of the doubt that exists in any measurement result. Every measurement in a laboratory, whether it is a molecular diagnostic assay, a biochemical test, or a calibration procedure, is subject to variation from multiple sources. These sources include the instrument, the operator, the reagents, the environmental conditions, and the sample itself. The uncertainty is not an error in the sense of a mistake. It is a description of the range within which the true value is expected to lie with a stated probability.

Laboratory professionals need to report uncertainty because the users of test results make decisions based on those results. A clinician who sees a viral load result of 12,400 copies/mL needs to know whether that value is meaningfully different from a previous result of 9,800 copies/mL. Without uncertainty information, the clinician cannot determine whether the difference is due to a true change in the patient's condition or to the inherent variability of the measurement method. The same principle applies to a researcher who compares measurements from different batches or a manufacturer who verifies that a product meets a specification.

The two main international standards that govern laboratory operations are ISO 15189 for medical laboratories and ISO 17025 for testing and calibration laboratories. Both standards require laboratories to estimate and report measurement uncertainty when it is relevant to the interpretation of the result. The standards do not require that every result carry a full uncertainty budget, but they do require that the laboratory knows the uncertainty of its methods and that it communicates this information to users when the uncertainty affects the interpretation of the result.

The National Institute of Standards and Technology (NIST) provides the foundational measurement science that supports these standards. NIST laboratories develop and maintain reference materials, calibration services, and measurement methods that allow laboratories to trace their results to a common reference. This traceability is the basis for comparing results across laboratories and over time. When a laboratory reports uncertainty, it should be able to trace its measurement to a reference standard through an unbroken chain of calibrations.

Core Principles of Measurement Uncertainty

The Measurand and the Measurement Model

The first step in uncertainty evaluation is to define the measurand. The measurand is the quantity that the laboratory intends to measure. In a viral load assay, the measurand is the concentration of viral RNA in the patient's plasma. In a quantitative PCR assay, the measurand might be the copy number of a specific gene in a DNA sample. The definition of the measurand must be specific enough that the uncertainty can be evaluated. A vague definition, such as "the amount of virus in the sample," is not sufficient because it does not specify the units, the sample matrix, or the method.

The measurement model is the mathematical relationship between the measurand and the quantities that are actually measured. In a quantitative PCR assay, the model might relate the cycle threshold value to the initial copy number through a standard curve. In a spectrophotometric assay, the model relates the absorbance to the concentration through the Beer-Lambert law. The model identifies the input quantities that contribute to the uncertainty of the final result.

Sources of Uncertainty

The sources of uncertainty in a laboratory measurement can be grouped into several categories. The first category is the instrument. The calibration of the instrument, its resolution, its drift over time, and its response to environmental conditions all contribute to the uncertainty. The second category is the operator. Different operators may pipette slightly differently, may read the instrument differently, or may follow the procedure with slightly different timing. The third category is the sample. The sample may not be homogeneous, the matrix may interfere with the measurement, and the sample may degrade during storage or processing. The fourth category is the method itself. The method may have a bias that is not fully corrected, the standard curve may not be perfectly linear, and the extraction efficiency may vary.

The evaluation of uncertainty requires that the laboratory identify all of the significant sources and quantify their contributions. This is done through a combination of statistical analysis of repeated measurements and the evaluation of the uncertainty of each input quantity. The combined uncertainty is then calculated by combining the individual contributions according to the rules of error propagation.

Standard Uncertainty and Expanded Uncertainty

The standard uncertainty is the uncertainty of the result expressed as a standard deviation. It is the basis for all further calculations. The expanded uncertainty is the standard uncertainty multiplied by a coverage factor. The coverage factor is chosen to provide a level of confidence. A coverage factor of k = 2 provides approximately 95% confidence, and a coverage factor of k = 3 provides approximately 99.7% confidence. The expanded uncertainty defines an interval around the measured value within which the true value is expected to lie with the stated probability.

The choice of the coverage factor depends on the level of confidence that the user needs. For most diagnostic applications, a coverage factor of k = 2 is used because it provides a 95% confidence interval. The laboratory should state the coverage factor and the confidence level in the report so that the user knows the meaning of the interval.

When to Report Uncertainty

The laboratory must decide when to include an uncertainty statement in the report. The decision depends on the purpose of the test, the needs of the user, and the requirements of the quality system.

Quantitative Results

Quantitative results are the primary candidates for uncertainty reporting. A quantitative result is a number with a unit, such as a concentration, a copy number, or an activity. The uncertainty of a quantitative result is meaningful to the user because it defines the range of values that are consistent with the measurement.

The laboratory should report the uncertainty for quantitative results when the result is used to make a decision. This includes results that are compared to a clinical decision limit, results that are used to monitor a patient over time, and results that are used to compare different samples. The laboratory should also report the uncertainty when the user requests it.

Qualitative Results

Qualitative results are reported as positive or negative, or as detected or not detected. The uncertainty of a qualitative result is not expressed as a numeric interval. Instead, the laboratory should report the limit of detection of the method and the confidence that the result is correct. The limit of detection is the lowest concentration that the method can reliably detect. The laboratory should state the limit of detection in the report so that the user knows the sensitivity of the method.

Results Near a Decision Limit

When a result is close to a clinical decision limit, the uncertainty is especially important. The user needs to know whether the result is truly above or below the limit. If the uncertainty interval includes the decision limit, the result is not definitive. The laboratory should flag such results and provide the uncertainty so that the user can make an informed decision.

For example, if the clinical decision limit for a viral load is 10,000 copies/mL and the measured result is 10,500 copies/mL with an expanded uncertainty of ± 1,800 copies/mL, the uncertainty interval extends from 8,700 to 12,300 copies/mL. This interval includes the decision limit, so the result is not definitive. The user should interpret the result with caution and may need to repeat the test.

User Requests

The laboratory should always provide the uncertainty when the user requests it. The user may need the uncertainty for a specific decision, for a comparison, or for a regulatory submission. The laboratory should have the uncertainty information available and should be able to provide it in a clear format.

The Uncertainty Budget

The uncertainty budget is a table that lists all of the sources of uncertainty, the value of each source, the type of distribution, and the contribution to the total uncertainty. The budget is the basis for the calculation of the standard uncertainty.

Building the Budget

The laboratory builds the budget by identifying all of the sources of uncertainty that are significant for the method. The sources are identified through a review of the method, the instrument, the reagents, and the environment. The laboratory then quantifies each source. Some sources are quantified by repeated measurements, and others are quantified by the evaluation of the method specifications.

The budget should include the following information for each source:

• The name of the source
• The value of the source, expressed as a standard deviation
• The type of the distribution (normal, rectangular, triangular)
• The degrees of freedom, if known

The total standard uncertainty is the square root of the sum of the squares of the individual contributions. This is the rule of the combination of the uncertainties.

Example of an Uncertainty Budget

The combined standard uncertainty is calculated as the square root of the sum of the squares of the individual contributions. In this example, the combined standard uncertainty is approximately 2.6% of the reading. The expanded uncertainty with a coverage factor of k = 2 is approximately 5.2% of the reading.

How to Calculate the Expanded Uncertainty

The expanded uncertainty is calculated by multiplying the combined standard uncertainty by the coverage factor. The coverage factor is chosen based on the level of confidence that is needed.

Step 1: Calculate the Combined Standard Uncertainty

The combined standard uncertainty is the square root of the sum of the squares of the individual standard uncertainties. This is the rule for the combination of the uncertainties of the input quantities.

Step 2: Choose the Coverage Factor

The coverage factor is chosen based on the level of confidence. A coverage factor of k = 1 provides a confidence of approximately 68%. A coverage factor of k = 2 provides a confidence of approximately 95%. A coverage factor of k = 3 provides a confidence of approximately 99.7%.

The choice of the coverage factor depends on the needs of the user. For most diagnostic applications, a coverage factor of k = 2 is used. The laboratory should state the coverage factor and the confidence level in the report.

Step 3: Calculate the Expanded Uncertainty

The expanded uncertainty is the product of the combined standard uncertainty and the coverage factor. The expanded uncertainty is reported as a range around the measured result.

Step 4: State the Result

The result is reported as the measured value plus or minus the expanded uncertainty, with the coverage factor and the confidence level stated. The unit of the uncertainty must be the same as the unit of the measured value.

Template for Reporting Uncertainty

The following template provides a standard format for reporting the uncertainty in a test report. The template can be adapted to the specific method and the needs of the laboratory.

Template for a Quantitative Result

Measured value: [value] [unit]
Expanded uncertainty: ± [value] [unit]
Coverage factor: k = [value]
Confidence level: approximately [value]%
Method: [method name and version]
Sample: [sample identifier]
Date of analysis: [date]

Example of a Completed Report

Measured value: 12,400 copies/mL
Expanded uncertainty: ± 1,800 copies/mL
Coverage factor: k = 2
Confidence level: approximately 95%
Method: RT-PCR, version 2.0
Sample: Patient sample 2024-00123
Date of analysis: 2024-11-15

Template for a Qualitative Test

Result: [positive or negative]
Limit of detection: [value] [unit]
Method: [method name]
Sample: [sample identifier]
Date of analysis: [date]

Example of a Completed Qualitative Report

Result: Positive
Limit of detection: 50 copies/mL
Method: RT-PCR, version 2.0
Sample: Patient sample 2024-00124
Date of analysis: 2024-11-15

Wording Examples for Different Situations

The wording of the uncertainty statement should be clear and should not be ambiguous. The user should be able to understand the meaning of the uncertainty without having to consult the laboratory.

Standard Wording for a Quantitative Result

"The measured value is 12,400 copies/mL. The expanded uncertainty is ± 1,800 copies/mL with a coverage factor of k = 2, which provides a confidence level of approximately 95%. The true value is expected to lie within the interval from 10,600 to 14,200 copies/mL."

Wording for a Result Near a Decision Limit

"The measured result is 10,500 copies/mL. The expanded uncertainty is ± 1,800 copies/mL with a coverage factor of k = 2. The uncertainty interval extends from 8,700 to 12,300 copies/mL. This interval includes the clinical decision limit of 10,000 copies/mL. The result is not definitive, and a repeat test is recommended."

Wording for a Result That Exceeds a Decision Limit

"The measured result is 15,000 copies/mL. The expanded uncertainty is ± 1,800 copies/mL with a coverage factor of k = 2. The lower limit of the uncertainty interval is 13,200 copies/mL, which is above the clinical decision limit of 10,000 copies/mL. The result is above the decision limit."

Wording for a Qualitative Result

"The result is positive. The limit of detection of the method is 50 copies/mL. The result indicates that the target is present in the sample."

When to Include the Uncertainty in the Report

The laboratory should include the uncertainty in the report when the result is used for a decision. The following situations require the uncertainty to be reported:

• The result is compared to a clinical decision limit.
• The result is used to monitor a patient over time.
• The result is used to compare different samples.
• The user requests the uncertainty.
• The laboratory's quality system requires the uncertainty to be reported.

The laboratory should not include the uncertainty in the report when the result is not used for a decision and the user does not request it. The inclusion of the uncertainty in every report can confuse the user and make the report difficult to read.

The Role of the Quality Control in the Uncertainty

The quality control of the laboratory is the basis of the uncertainty evaluation. The quality control data provide the information that is needed to estimate the uncertainty of the method. The laboratory should use the quality control data to evaluate the uncertainty and to update the uncertainty when the method changes.

Internal Quality Control

The internal quality control is the daily monitoring of the method. The laboratory runs control samples with known values and compares the measured values to the expected values. The control data provide the information about the precision of the method. The standard deviation of the control data is a measure of the uncertainty of the method.

External Quality Control

The external quality control is the comparison of the laboratory's results with the results of other laboratories. The external quality control provides the information about the bias of the method. The bias is the difference between the laboratory's results and the true value. The bias is a component of the uncertainty.

The Control Chart

The control chart is a graphical display of the control data over time. The control chart shows the trend of the method and the variation of the method. The control chart is used to detect the changes in the method that affect the uncertainty.

The Validation of the Method and the Uncertainty

The validation of the method is the process of demonstrating that the method is suitable for its intended purpose. The validation provides the data that are needed to estimate the uncertainty of the method.

The Validation Parameters

The validation parameters include the accuracy, the precision, the limit of detection, the limit of quantification, the linearity, and the specificity. Each of these parameters contributes to the uncertainty of the method.

The Accuracy

The accuracy is the closeness of the measured value to the true value. The accuracy is evaluated by the analysis of the reference materials or by the comparison with a reference method. The bias of the method is the difference between the measured value and the true value. The bias is a component of the uncertainty.

The Precision

The precision is the closeness of the repeated measurements to each other. The precision is evaluated by the repeated analysis of the same sample. The standard deviation of the repeated measurements is a measure of the precision. The precision is a component of the uncertainty.

The Limit of Detection and the Limit of Quantification

The limit of detection is the lowest concentration that the method can detect. The limit of quantification is the lowest concentration that the method can quantify with a stated precision. The limit of detection and the limit of quantification are components of the uncertainty for the results near the limit.

The Linearity

The linearity is the ability of the method to provide results that are proportional to the concentration of the analyte. The linearity is evaluated by the analysis of the samples with known concentrations. The deviation from the linearity is a component of the uncertainty.

The Specificity

The specificity is the ability of the method to measure the analyte in the presence of the other components of the sample. The specificity is evaluated by the analysis of the samples that contain the interfering substances. The interference is a component of the uncertainty.

The Use of the Reference Materials

The reference materials are the materials with known values that are used to calibrate the method and to evaluate the accuracy. The reference materials are the basis of the traceability of the method.

The Types of the Reference Materials

The reference materials include the certified reference materials, the reference materials, and the control materials. The certified reference materials are the materials with the values that are certified by the reference laboratory. The reference materials are the materials with the values that are established by the laboratory. The control materials are the materials used for the daily control of the method.

The Use of the Reference Materials

The reference materials are used to calibrate the method, to evaluate the accuracy, and to verify the method. The reference materials are also used to evaluate the uncertainty of the method.

The Traceability of the Method

The traceability of the method is the chain of the calibrations that connects the method to the national standards. The traceability is the basis of the comparability of the results. The NIST provides the reference materials and the calibration services that are used to establish the traceability.

The Evaluation of the Uncertainty

The evaluation of the uncertainty is the process of the identification and the quantification of the sources of the uncertainty. The evaluation is based on the data from the validation, the quality control, and the method specifications.

The Type A Evaluation

The Type A evaluation is the evaluation of the uncertainty by the statistical analysis of the repeated measurements. The Type A evaluation is based on the standard deviation of the repeated measurements.

The Type B Evaluation

The Type B evaluation is the evaluation of the uncertainty by the other means. The Type B evaluation is based on the specifications of the instrument, the calibration certificates, and the experience of the laboratory.

The Combination of the Uncertainty

The combination of the uncertainty is the calculation of the total uncertainty from the individual contributions. The combination is based on the rule of the propagation of the uncertainty.

The Reporting of the Uncertainty in the Test Report

The test report is the document that the laboratory provides to the user. The report contains the result of the test and the information that the user needs to interpret the result. The report should include the uncertainty when the uncertainty is relevant to the interpretation of the result.

The Structure of the Report

The report should have a clear structure. The report should include the following information:

• The identification of the sample
• The identification of the method
• The result of the test
• The uncertainty of the result
• The interpretation of the result

The Identification of the Sample

The report should identify the sample. The identification should include the sample identifier, the type of the sample, and the date of the collection.

The Identification of the Method

The report should identify the method. The identification should include the name of the method, the version of the method, and the reference of the method.

The Result of the Test

The report should state the result of the test. The result should be stated with the unit of the measurement.

The Uncertainty of the Result

The report should state the uncertainty of the result. The uncertainty should be stated as the expanded uncertainty with the coverage factor and the confidence level.

The Interpretation of the Report

The report should provide the interpretation of the result. The interpretation should include the comparison of the result to the decision limit and the guidance for the user.

The Use of the Uncertainty in the Interpretation

The uncertainty is used to interpret the result. The user should use the uncertainty to determine whether the result is different from the decision limit or from the previous result.

The Comparison to the Decision Limit

The user should compare the uncertainty interval to the decision limit. If the uncertainty interval does not include the decision limit, the result is definitive. If the uncertainty interval includes the decision limit, the result is not definitive.

The Comparison to the Previous Result

The user should compare the uncertainty interval to the previous result. If the uncertainty intervals of the two results do not overlap, the difference is significant. If the uncertainty intervals overlap, the difference is not significant.

The Use of the Uncertainty in the Monitoring

The user should use the uncertainty to monitor the patient over time. The user should compare the uncertainty interval of the current result to the uncertainty interval of the previous result. If the intervals do not overlap, the change is significant.

The Common Failure Patterns in the Uncertainty Reporting

The laboratory should be aware of the common failure patterns in the reporting of the uncertainty. The failure patterns can lead to the confusion of the user and the misinterpretation of the result.

The Failure to Report the Uncertainty

The most common failure is the failure to report the uncertainty. The laboratory may not report the uncertainty because the laboratory does not have the uncertainty data or because the laboratory does not know when to report the uncertainty.

The Failure to State the Coverage Factor

The laboratory may report the uncertainty without stating the coverage factor. The user cannot interpret the uncertainty without the coverage factor.

The Failure to State the Confidence Level

The laboratory may report the uncertainty without stating the confidence level. The user cannot know the probability that the true value is within the interval.

The Failure to Use the Correct Unit

The laboratory may report the uncertainty with the incorrect unit. The uncertainty must be reported in the same unit as the measured result.

The Failure to Update the Uncertainty

The laboratory may continue to use the uncertainty data that are outdated. The laboratory should update the uncertainty data when the method changes or when the quality control data indicate a change.

The Limitations of the Uncertainty

The uncertainty is a useful tool for the interpretation of the results, but it has limitations. The user should be aware of the limitations of the uncertainty.

The Uncertainty Is Not the Error

The uncertainty is not the error of the measurement. The uncertainty is the range of the values that are consistent with the measured result. The error is the difference between the measured result and the true value. The error is not known.

The Uncertainty Is Not the Tolerance

The uncertainty is not the tolerance of the method. The tolerance is the range of the values that the method is expected to provide. The uncertainty is the range of the values that is the measured result.

The Uncertainty Is Not the Specification

The uncertainty is not the specification of the method. The specification is the requirement of the method. The uncertainty is the description of the method.

The Uncertainty Is Not the Precision

The uncertainty is not the precision of the method. The precision is the variation of the repeated measurements. The uncertainty includes the precision and the other sources of the variation.

The Professional Escalation Criteria

The laboratory should escalate the issue to the professional when the issue is beyond the scope of the laboratory. The escalation criteria include the following:

• The uncertainty is larger than the acceptable limit
• The uncertainty is not consistent with the quality control data
• The uncertainty is not consistent with the validation data
• The user does not understand the uncertainty
• The user requests the uncertainty that the laboratory cannot provide

The Biosafety and the Safety Context

The laboratory should follow the biosafety and the safety guidelines when the laboratory is performing the tests. The biosafety guidelines are provided by the CDC and the NIH. The guidelines describe the containment of the biological agents and the risk assessment of the laboratory.

The laboratory should follow the biosafety level that is appropriate for the agents that are handled. The biosafety level is determined by the risk assessment of the agents. The risk assessment is based on the infectivity, the severity of the disease, the mode of the transmission, and the availability of the treatment.

The laboratory should also follow the NIH guidelines for the recombinant and the synthetic nucleic acid molecules. The guidelines describe the oversight of the research that involves the recombinant and the synthetic nucleic acid molecules. The laboratory should follow the guidelines when the laboratory is the research that involves the recombinant or the synthetic nucleic acid molecules.

The laboratory should also follow the protocols for the molecular biology workflows. The protocols provide the practical guidance for the planning and the execution of the molecular biology experiments. The protocols are not the universal validation of the method, and the laboratory should validate the method for the specific application.

The Records and the Measurements

The laboratory should maintain the records of the uncertainty evaluation. The records should include the following:

• The uncertainty budget
• The validation data
• The quality control data
• The calibration data
• The method specifications

The records should be maintained for the period that is required by the quality system. The records should be available for the review by the user and the auditor.

The Practical Implementation of the Uncertainty Reporting

The laboratory should implement the uncertainty reporting in a systematic way. The implementation should include the following steps:

Step 1: Identify the Methods That Need the Uncertainty

The laboratory should identify the methods that need the uncertainty. The methods that are used for the decision should be the priority.

Step 2: Evaluate the Uncertainty of the Methods

The laboratory should evaluate the uncertainty of the methods. The evaluation should be based on the validation data and the quality control data.

Step 3: Document the Uncertainty

The laboratory should document the uncertainty of the methods. The documentation should include the uncertainty budget and the calculation of the uncertainty.

Step 4: Train the Staff

The laboratory should train the staff on the reporting of the uncertainty. The staff should know when to report the uncertainty and how to report the uncertainty.

Step 5: Implement the Reporting

The laboratory should implement the reporting of the uncertainty in the test reports. The implementation should include the template and the wording.

Step 6: Monitor the Reporting

The laboratory should monitor the reporting of the uncertainty. The monitoring should include the review of the reports and the feedback of the users.

The Assessment of the Uncertainty Reporting

The laboratory should assess the uncertainty reporting on a regular basis. The assessment should include the following:

• The review of the reports
• The review of the uncertainty data
• The review of the user feedback
• The review of the quality control data

The assessment should identify the areas for the improvement. The improvement should be implemented and the assessment should be repeated.

The Common Failure Patterns in the Uncertainty Evaluation

The common failure patterns in the uncertainty evaluation include the following:

The Failure to Identify All the Sources

The laboratory may fail to identify all the sources of the uncertainty. The laboratory should review the method and the environment to identify all the sources.

The Failure to Quantify the Sources

The laboratory may fail to quantify the sources of the uncertainty. The laboratory should use the validation data and the quality control data to quantify the sources.

The Failure to Combine the Sources

The laboratory may fail to combine the sources of the uncertainty. The laboratory should use the rule of the combination of the squares.

The Failure to Update the Uncertainty

The laboratory may fail to update the uncertainty when the method changes. The laboratory should update the uncertainty when the method is changed or when the quality control data indicate a change.

The Records and the Measurements

The laboratory should keep the records of the uncertainty evaluation. The records should include the following:

• The uncertainty budget
• The validation data
• The quality control data
• The calibration data
• The method specifications

The records should be kept for the period that is required by the quality system. The records should be available for the review of the user and the auditor.

The Common Failure Patterns in the Reporting

The common failure patterns in the reporting of the uncertainty include the following patterns:

The Failure to Report the Uncertainty

The laboratory may fail to report the uncertainty. The laboratory should report the uncertainty when the result is used for the decision.

The Failure to State the Coverage Factor

The laboratory may report the uncertainty without the coverage factor. The laboratory should state the coverage factor and the confidence level.

The Failure to State the Unit

The laboratory may report the uncertainty with the wrong unit. The laboratory should report the uncertainty in the same unit as the measured result.

The Failure to Provide the Interpretation

The laboratory may fail to provide the interpretation of the result. The laboratory should provide the interpretation of the result and the guidance for the user.

The Professional Escalation Criteria

The laboratory should escalate the issue to the professional when the issue is beyond the scope of the laboratory. The escalation criteria include the following:

• The uncertainty is larger than the acceptable limit
• The uncertainty is not consistent with the quality control data
• The uncertainty is not consistent with the validation data
• The user does not understand the uncertainty
• The user is not able to use the uncertainty

The Biosafety and the Safety

The laboratory should follow the biosafety and the safety guidelines. The biosafety guidelines are provided by the CDC and the NIH. The guidelines describe the containment of the biological agents and the risk assessment of the laboratory.

The laboratory should follow the biosafety level that is appropriate for the agents that are handled. The biosafety level is determined by the risk assessment of the agents.

The laboratory should also follow the NIH guidelines for the recombinant and the synthetic nucleic acid molecules. The guidelines describe the oversight of the research that involves the recombinant and the synthetic nucleic acid molecules.

The laboratory should also follow the protocols for the molecular biology workflows. The protocols provide the guidance for the molecular biology experiments.

The Professional Escalation Criteria

The laboratory should escalate the issue to the professional when the issue is beyond the scope of the laboratory. The escalation criteria include the following:

• The uncertainty is larger than the acceptable limit
• The uncertainty is not consistent with the quality control data
• The uncertainty is not consistent with the validation data
• The user does not understand the uncertainty
• The user is not able to use the uncertainty

The Biosafety and the Safety

The laboratory should follow the biosafety and the safety guidelines. The biosafety guidelines are provided by the CDC and the NIH. The guidelines describe the containment of the biological agents and the risk assessment of the laboratory.

The laboratory should follow the biosafety level that is appropriate for the agents that are handled. The biosafety level is determined by the risk assessment of the agents.

The laboratory should also follow the NIH guidelines for the recombinant and the synthetic nucleic acid molecules. The guidelines describe the oversight of the research that involves the recombinant and the synthetic nucleic acid molecules.

The laboratory should also follow the protocols for the molecular biology workflows. The protocols provide the guidance for the molecular biology of the experiments.

The Professional Escalation Criteria

The laboratory should escalate the issue to the professional when the issue is beyond the scope of the laboratory. The escalation criteria include the following:

• The uncertainty is larger than the acceptable limit
• The uncertainty is not consistent with the quality control data
• The uncertainty is not consistent with the validation data
• The user does not understand the uncertainty
• The user is not able to use the uncertainty

The Biosafety and the Safety

The laboratory should follow the biosafety and the safety guidelines. The biosafety guidelines are provided by the CDC and the NIH. The guidelines describe the containment of the biological agents and the risk assessment of the laboratory.

The laboratory should follow the biosafety level that is appropriate for the agents that are handled. The biosafety level is determined by the risk assessment of the agents.

The laboratory should also follow the NIH guidelines for the recombinant and the synthetic nucleic acid molecules. The guidelines describe the oversight of the research that involves the recombinant and the synthetic nucleic acid molecules.

The laboratory should also follow the protocols for the molecular biology workflows. The protocols provide the guidance for the molecular biology of the laboratories.

Frequently Asked Questions

What is the difference between the standard uncertainty and the expanded uncertainty?

The standard uncertainty is the uncertainty of the result expressed as a standard deviation. The expanded uncertainty is the standard uncertainty multiplied by a coverage factor. The expanded uncertainty defines the interval around the measured result within which the true value is expected to lie with a stated probability.

When should the laboratory report the uncertainty?

The laboratory should report the uncertainty when the result is used to make a decision. This includes results that are compared to a clinical decision limit, results that are used to monitor a patient over time, and results that are used to compare different samples. The laboratory should also report the uncertainty when the user requests it.

What is the coverage factor?

The coverage factor is the factor that is used to calculate the expanded uncertainty from the standard uncertainty. A coverage factor of k = 2 provides a confidence level of approximately 95%. A coverage factor of k = 3 provides a confidence level of approximately 99.7%.

How does the laboratory evaluate the uncertainty?

The laboratory evaluates the uncertainty by identifying the sources of the uncertainty, quantifying the contributions of the sources, and combining the contributions according to the rule of the combination of the squares. The evaluation is based on the validation data and the quality control data.

What is the uncertainty budget?

The uncertainty budget is a table that lists the sources of the uncertainty, the contribution of each source, and the total uncertainty. The budget is the basis of the calculation of the total uncertainty.

How does the user use the uncertainty?

The user uses the uncertainty to determine whether the result is different from the decision limit or from the previous result. The user compares the uncertainty interval to the decision limit or to the previous result. If the interval does not include the decision limit, the result is definitive. If the interval includes the decision limit, the result is not definitive.

What is the limit of detection?

The limit of detection is the lowest concentration that the method can detect. The limit of detection is reported for the qualitative results. The limit of detection is a component of the uncertainty for the results near the limit.

What is the traceability of the method?

The traceability of the method is the chain of the calibrations that connects the method to the national standards. The traceability is the basis of the comparability of the results. The NIST provides the reference standards and the calibration services that are used to establish the traceability.

Related Diagnostic Guides

• Measurement Uncertainty in Laboratory Medicine: A Guide to Calculation and Reporting
• ISO 17025 vs ISO 15189: Choosing the Right Quality Standard for Your Laboratory
• Laboratory Quality Management System: A Guide to ISO 15189 Accreditation
• Laboratory Inspection Checklists: Ensuring Compliance with CAP and ISO Standards

References and Further Reading

• Molecular Biology and Laboratory Methods. National Library of Medicine.
• Biosafety in Microbiological and Biomedical Laboratories. CDC and NIH.
• NIH Guidelines for Recombinant or Synthetic Nucleic Acid Molecules. National Institutes of Health.
• Addgene Protocols. Addgene.
• MIQE Guidelines. Clinical Chemistry.
• NIST Laboratory Programs. National Institute of Standards and Technology.
• Laboratory Biosafety Manual. World Health Organization.
• NCBI Literature Resources. National Center for Biotechnology Information.
• Use of Delphi in health sciences research: A narrative review.. Medicine, 2023.
• A Simple Guide to Effect Size Measures.. JAMA otolaryngology-- head & neck surgery, 2023.
• Assessment of Clinical Reasoning in Healthcare Students via the Script Concordance Test: Situations in Anesthesia and Intensive Care.. La Tunisie medicale, 2024.

This article is educational and does not replace validated laboratory procedures, institutional biosafety review, manufacturer instructions, or professional interpretation.