Size-Exclusion Chromatography for Assessing Protein Aggregation and Stability

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

Quick Answer

Choose a size-exclusion chromatography column resin based on the molecular weight range of your target protein and the aggregate species you need to resolve, then verify resolution with a standard protein mixture.
Optimize mobile phase composition to preserve native protein interactions, using a physiological pH and ionic strength that match your protein's stability requirements.
Interpret chromatograms by comparing retention volumes against molecular weight standards, but confirm peak identity with an orthogonal method because size-exclusion chromatography cannot distinguish size from shape or protein-protein interactions.

At a Glance

Decision Point	Consideration	Practical Action
Column resin selection	Pore size determines the molecular weight range that can be resolved	Match the resin's fractionation range to your protein's molecular weight and expected aggregate sizes
Mobile phase composition	pH, ionic strength, and additives affect protein stability and column interactions	Use a buffer that maintains protein solubility and prevents non-specific binding to the resin
Sample preparation	Aggregates can form during storage, freeze-thaw, or concentration steps	Centrifuge or filter samples before injection to remove particulates and large aggregates
Detection method	UV absorbance at 280 nm is standard, but some proteins lack aromatic residues	Use a detection wavelength appropriate for your protein or employ a more sensitive detection method
Data interpretation	Retention time correlates with molecular size, but shape and interactions can alter elution	Compare to standards and confirm with an orthogonal technique such as dynamic light scattering
Column maintenance	Resin degradation and contamination affect reproducibility	Follow the manufacturer's cleaning and storage recommendations and monitor column performance with standards

Understanding Size-Exclusion Chromatography

Size-exclusion chromatography separates molecules based on their hydrodynamic volume, which is the effective size of a molecule in solution. The stationary phase consists of porous beads with a defined pore size distribution. Molecules that are larger than the largest pores cannot enter the beads and elute first. Smaller molecules can penetrate the pores to varying degrees and therefore take longer to travel through the column. This mechanism is distinct from other chromatographic methods because it does not rely on chemical interactions between the sample and the stationary phase.

The separation range of a given column is determined by the pore size of the resin. A resin with larger pores can accommodate larger molecules, while a resin with smaller pores is suited for smaller molecules. The fractionation range is the range of molecular weights that can be separated within the column. Molecules that are larger than the upper limit of the fractionation range elute in the void volume, which is the volume of the column that is not occupied by the resin. Molecules that are smaller than the lower limit of the fractionation range elute in the total volume, which is the volume of the column that is accessible to the smallest molecules.

The Role of Hydrodynamic Volume

The hydrodynamic volume of a protein is not always directly proportional to its molecular weight. A protein with an elongated shape has a larger hydrodynamic volume than a globular protein of the same molecular weight. This means that an elongated protein may elute earlier than a globular protein of the same mass. Similarly, a protein that is partially unfolded may have a larger hydrodynamic volume than its native, folded state. This is an important consideration when interpreting size-exclusion chromatography data, because a change in retention time can indicate a change in size, a change in shape, or both.

Column Selection

Choosing the right column is the first step in developing a size-exclusion chromatography method. The fractionation range of the column should be appropriate for the molecular weight of your target protein and the size of the aggregates you want to detect. For example, if you are studying a monomeric protein of 50 kDa and you want to detect dimers and higher-order aggregates, you need a column that can resolve molecules in the range of approximately 50 to 300 kDa. If you are studying a larger protein complex, you may need a column with a wider fractionation range.

The particle size of the resin also affects the resolution. Smaller particles provide better resolution but generate higher back pressure. The column length also affects resolution, with longer columns providing better separation but longer run times. The choice of column is a tradeoff between resolution, speed, and pressure.

Mobile Phase Selection

The mobile phase is the buffer that carries the sample through the column. The composition of the mobile phase is important for two reasons. First, it must maintain the stability of the protein. A buffer that is not compatible with the protein can cause it to unfold, aggregate, or precipitate. Second, the mobile phase must prevent non-specific interactions between the protein and the column resin. These interactions can cause the protein to elute later than expected or to be retained on the column.

The pH of the mobile phase should be within the range that maintains the protein's native structure. The ionic strength of the mobile phase is also important. A moderate ionic strength, such as 150 mM sodium chloride, is often used to reduce non-specific interactions. Some proteins may require the addition of a reducing agent, such as dithiothreitol, to prevent oxidation of cysteine residues. Other proteins may require the addition of a cofactor or a ligand to maintain their stability.

Sample Preparation

The quality of the sample is a major factor in the success of a size-exclusion chromatography experiment. The sample should be free of particulates and large aggregates that can clog the column. Centrifugation or filtration of the sample before injection is a common practice. The sample should also be in a buffer that is compatible with the mobile phase. If the sample is in a different buffer, it may need to be exchanged before analysis.

The concentration of the sample is also important. A sample that is too concentrated may cause the protein to aggregate during the run. A sample that is too dilute may not produce a detectable signal. The optimal concentration depends on the detection method and the sensitivity of the instrument.

Practical Workflow for Size-Exclusion Chromatography

Step 1: Define the Question

Before starting a size-exclusion chromatography experiment, define the question you want to answer. Are you trying to determine the molecular weight of a protein? Are you trying to detect the presence of aggregates? Are you trying to separate a monomer from a dimer? The answer to this question will determine the choice of column, mobile phase, and detection method.

Step 2: Select the Column

Select a column with a fractionation range that covers the molecular weight of your protein and the size of the species you want to resolve. If you are working with a protein of unknown size, you may need to use a column with a wide fractionation range. The column should be compatible with the mobile phase you plan to use.

Step 3: Prepare the Mobile Phase

Prepare the mobile phase buffer with the appropriate pH and ionic strength. The buffer should be filtered and degassed to remove particles and dissolved gases. The buffer should be prepared fresh and used within a reasonable time to prevent microbial growth.

Step 4: Prepare the Sample

Centrifuge the sample to remove particulates and large aggregates. If the sample is in a different buffer, consider dialyzing or diluting it to match the mobile phase. The sample should be at a concentration that is appropriate for the detection method.

Step 5: Run the Standards

Run a set of molecular weight standards to calibrate the column. The standards should cover the range of molecular weights that you expect to see in your sample. The retention times of the standards are used to create a calibration curve that relates retention time to molecular weight.

Step 6: Run the Sample

Inject the sample and record the chromatogram. The chromatogram will show peaks that correspond to the different species in the sample. The retention time of each peak can be used to estimate the molecular weight of the species.

Step 7: Analyze the Data

Compare the retention times of the sample peaks to the calibration curve. The molecular weight of each peak can be estimated from the calibration curve. The area under each peak can be used to estimate the relative amount of each species.

Step 8: Confirm the Results

Size-exclusion chromatography is a powerful method, but it has limitations. The results should be confirmed with an independent method, such as mass spectrometry or dynamic light scattering. This is especially important when the results are used to make decisions about the quality of a protein.

Column Resin Selection

Pore Size and Fractionation Range

The pore size of the resin is the most important factor in determining the fractionation range of a column. The pore size is measured in angstroms and is related to the size of the molecules that can enter the pores. A resin with a larger pore size can accommodate larger molecules. The fractionation range of a column is the range of molecular weights that can be separated by the column.

The choice of resin depends on the size of the protein and the aggregates you want to detect. For a small protein, a resin with a smaller pore size is appropriate. For a large protein or a protein complex, a resin with a larger pore size is needed. The fractionation range of the column should be matched to the size of the molecules you want to separate.

Particle Size and Resolution

The particle size of the resin affects the resolution of the column. Smaller particles provide better resolution because they allow for more efficient mass transfer. However, smaller particles also generate higher back pressure. The choice of particle size is a trade-off between resolution and pressure.

Column Dimensions

The length and diameter of the column also affect the resolution. A longer column provides better resolution because it allows more time for the separation to occur. However, a longer column also increases the run time and the back pressure. The diameter of the column affects the sample capacity. A wider column can accommodate a larger sample volume.

Resin Chemistry

The chemistry of the resin is also important. The resin should be inert and should not interact with the protein. Some resins are coated with a layer of a hydrophilic polymer to prevent non-specific interactions. The resin should also be stable in the mobile phase that you plan to use.

Mobile Phase Optimization

pH and Ionic Strength

The pH of the mobile phase is a critical factor in maintaining the stability of the protein. The pH should be close to the isoelectric point of the protein, but it should be in a range where the protein is stable. The ionic strength of the mobile phase is also important. A moderate ionic strength is used to prevent non-specific interactions between the protein and the resin.

Additives

The mobile phase may contain additives to improve the stability of the protein or to prevent non-specific interactions. A reducing agent may be added to prevent the oxidation of cysteine residues. A chelating agent may be added to remove metal ions that can catalyze oxidation. A small amount of a solvent may be added to prevent hydrophobic interactions.

Degassing and Filtration

The mobile phase should be degassed to remove dissolved gases that can form bubbles in the system. The mobile phase should also be filtered to remove particles that can clog the column. The mobile phase should be prepared fresh and used within a reasonable time.

Detection and Data Analysis

UV Detection

UV detection is the most common method for detecting proteins in size-exclusion chromatography. Proteins absorb UV light at 280 nm due to the presence of aromatic amino acids. The absorbance at 280 nm is proportional to the concentration of the protein. However, the absorbance at 280 nm is not the same for all proteins. A protein that lacks aromatic amino acids may have a low absorbance at 280 nm.

Other Detection Methods

Other detection methods can be used to detect proteins that do not absorb UV light well. Fluorescence detection is more sensitive than UV detection. Mass spectrometry can be used to identify the molecular weight of the species in the sample. Light scattering can be used to measure the molecular weight of the species in the sample.

Calibration and Standards

The retention time of a protein in size-exclusion chromatography is related to its hydrodynamic volume. To estimate the molecular weight of a protein, the column is calibrated with standards of known molecular weight. The retention times of the standards are plotted against the log of the molecular weight. The molecular weight of the sample can be estimated from the calibration curve.

Limitations of Calibration

The calibration curve is based on the assumption that the standards and the sample have the same shape. If the sample has a different shape than the standards, the molecular weight estimate may be inaccurate. The calibration curve is also affected by the mobile phase and the column.

Common Failure Patterns

Non-Specific Interactions

Non-specific interactions between the protein and the resin can cause the protein to elute later than expected. This can be caused by the protein being positively charged and the resin being negatively charged. The addition of a salt to the mobile phase can suppress these interactions.

Protein Aggregation

Protein aggregation can occur during the run. This can be caused by the protein being unstable in the mobile phase. The aggregation can be detected by the presence of a peak at the void volume. The aggregation can be prevented by changing the mobile phase or by adding a stabilizing agent.

Column Clogging

The column can be clogged by particulate matter in the sample. The clogging can cause an increase in the back pressure and a decrease in the resolution. The column can be cleaned by following the manufacturer's instructions.

Poor Resolution

Poor resolution can be caused by a column that is not appropriate for the sample. The resolution can be improved by using a column with a smaller particle size or a longer column. The resolution can also be improved by changing the mobile phase.

Records and Measurements

Documentation

The documentation of the size-exclusion chromatography experiment is important for reproducibility. The following information should be recorded: the column type, the mobile phase composition, the flow rate, the sample volume, the detection wavelength, and the retention times of the standards and the sample.

Data Analysis

The data from the size-exclusion chromatography experiment should be analyzed to determine the molecular weight of the species in the sample. The area under each peak can be used to estimate the relative amount of each species. The data should be compared to the calibration curve.

Quality Control

The quality of the size-exclusion chromatography experiment should be monitored. The column should be tested with a standard to ensure that it is performing correctly. The mobile phase should be checked for the presence of bubbles or particles.

Safety and Regulatory Context

Biosafety

The handling of biological samples requires adherence to biosafety principles. The risk assessment should be based on the nature of the sample and the procedures being performed. The use of a biological safety cabinet may be required for certain samples. The institutional biosafety committee should be consulted for guidance on the appropriate containment level.

Recombinant DNA

If the protein is produced from a recombinant organism, the work may be subject to the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules. The guidelines provide a framework for the safe handling of recombinant organisms. The institutional biosafety committee should be consulted to determine the appropriate containment level.

Laboratory Standards

The quality of the size-exclusion chromatography experiment should be monitored. The use of standards and the calibration of the instrument are important for the accuracy of the results. The laboratory should follow the standards for the measurement of the protein.

Professional Escalation Criteria

When to Seek Help

If the size-exclusion chromatography results are not reproducible, the column may be damaged or the mobile phase may be incorrect. If the protein is not eluting as expected, the protein may be unstable or the column may be inappropriate. If the results are not consistent with the expected molecular weight, the protein may be a different shape than expected.

When to Consult a Specialist

If the size-exclusion chromatography method is not working, a specialist in the field of protein chemistry should be consulted. The specialist can help to troubleshoot the method and to select the appropriate column and mobile phase.

A Decision Framework for Matching Column Resin to Aggregate Size Targets

Selecting a size-exclusion chromatography column is often treated as a one-time choice based on the monomer molecular weight, but the real analytical target is the aggregate distribution. A column that resolves a monomer from a dimer may fail to resolve a dimer from a trimer, and a column that separates small oligomers may exclude very large soluble aggregates entirely. This section provides a decision framework that connects your aggregate size question to a specific column selection, a mobile phase screening plan, and a record system that captures the performance limits of your method.

Define the Aggregate Size Range You Must Detect

Before any column catalog is opened, write down the molecular weight of the monomer and the species you need to quantify. For a 50 kDa monomer, the relevant species are typically the dimer at 100 kDa, trimer at 150 kDa, and higher order oligomers. For a 150 kDa antibody, the dimer is 300 kDa and higher order aggregates may exceed 600 kDa. The upper bound of your detection range is the largest aggregate that matters for your product quality or research question. The lower bound is the monomer itself.

The fractionation range of a size-exclusion resin is the molecular weight interval over which molecules are separated based on size. Molecules above the upper limit elute in the void volume and are not resolved from each other. Molecules below the lower limit elute in the total volume and are also unresolved. If your aggregate of interest falls outside the fractionation range, the column cannot quantify it. This is the most common reason a size-exclusion method fails to detect a known aggregate population.

A practical rule is to select a column whose fractionation range covers from at least one third of the monomer molecular weight to at least three times the largest aggregate you need to measure. This margin ensures that the monomer does not elute near the total volume and that the largest aggregate does not elute near the void. For a 50 kDa monomer with a target of detecting up to hexamers at 300 kDa, the fractionation range should span roughly 15 to 900 kDa. For a 150 kDa antibody with a target of detecting up to tetramers at 600 kDa, the range should span roughly 50 to 1800 kDa.

Match Pore Size to the Aggregate Distribution

The pore size of the resin determines the fractionation range. Resins with larger pores fractionate larger molecules. A resin designed for small proteins in the 10 to 100 kDa range will not resolve a 300 kDa aggregate. A resin designed for large proteins in the 100 to 1000 kDa range will not resolve a 20 kDa monomer from a 40 kDa dimer because both will elute near the total volume.

The selection process is a direct mapping from the aggregate size range to the resin pore size. For a small protein of 20 to 30 kDa, a resin with a fractionation range of 10 to 100 kDa is appropriate. For a medium protein of 50 to 80 kDa, a resin with a range of 30 to 300 kDa is appropriate. For a large protein or antibody of 150 kDa, a resin with a range of 100 to 1000 kDa is appropriate. For a very large protein complex or virus-like particle above 500 kDa, a resin with a range of 500 to 5000 kDa is needed.

The particle size of the resin is a separate decision. Smaller particles, typically in the 1.7 to 5 micrometer range, provide higher resolution but generate higher back pressure. Larger particles, in the 10 to 30 micrometer range, generate lower back pressure but provide lower resolution. For a first method, a particle size of 5 to 10 micrometers is a reasonable balance. If the resolution between the monomer and dimer is insufficient, a smaller particle size column of the same chemistry can be tested.

Use a Two Column Screening Approach

When the aggregate distribution is unknown, a single column may not be sufficient. A practical approach is to run the sample on two columns with different fractionation ranges. The first column should have a wide fractionation range that covers the monomer and the largest expected aggregate. The second column should have a narrower range optimized for the monomer and the smallest oligomers. This two-column screen reveals whether the aggregate population is dominated by small oligomers or by large species that elute at the void.

The wide-range column is used to determine the overall distribution. If a significant peak appears at the void volume, the sample contains aggregates larger than the upper limit of the column. The size of these aggregates cannot be determined on this column. The narrow-range column is used to resolve the monomer from the dimer and trimer. If the monomer and dimer are not resolved on the wide-range column, the narrow-range column provides the needed resolution.

This two-column approach is a screening method, not a final method. The data from both columns are used to decide which column is appropriate for the routine assay. If the wide-range column shows a single monomer peak and no void peak, the narrow-range column may be unnecessary. If the wide-range column shows a void peak, the narrow-range column will not resolve the large aggregates, and a different column with a larger pore size is needed.

Screen the Mobile Phase for Aggregate Stability

The mobile phase composition is the second major decision after column selection. The mobile phase must maintain the protein in its native state and prevent non-specific interactions with the resin. A standard starting point is a phosphate-buffered saline at pH 7.4 with 150 mM sodium chloride. This buffer is compatible with many proteins and provides a moderate ionic strength that suppresses electrostatic interactions with the resin.

However, the standard buffer is not appropriate for every protein. A protein that is unstable at pH 7.4 may require a buffer at a different pH. A protein that requires a metal cofactor may need the cofactor added to the mobile phase. A protein that is prone to oxidation may need a reducing agent. The mobile phase should be screened in a small set of conditions to identify the buffer that maintains the monomer peak and minimizes the aggregate peak.

A practical screening plan uses three to five mobile phase conditions. The first condition is the standard phosphate-buffered saline. The second condition is the same buffer with a higher ionic strength, such as 300 mM sodium chloride. The third condition is the same buffer with a different pH, such as pH 6.5 or pH 8.0. The fourth condition is the standard buffer with a stabilizing additive, such as 5% glycerol or a mild detergent. The fifth condition is the standard buffer with a reducing agent, such as 1 mM dithiothreitol.

Each condition is run with the same sample and the same column. The chromatograms are compared for the monomer peak shape, the aggregate peak area, and the recovery. The condition that produces the sharpest monomer peak, the smallest aggregate peak, and the highest recovery is the best mobile phase for the protein. This screening is a practical step that can be completed in a single day with a small sample volume.

Use a Standard Mixture to Verify Resolution

A column that is new or has been stored for a long time should be tested with a standard protein mixture before the sample is run. The standard mixture should contain proteins of known molecular weight that span the fractionation range of the column. The mixture should include a protein near the upper limit of the range, a protein near the lower limit, and one or two proteins in between.

The standard run is used to verify that the column is performing correctly. The retention times of the standard proteins should be recorded and compared to the expected values. The resolution between adjacent standard peaks should be calculated. If the resolution is below the expected value, the column may be damaged or the mobile phase may be incorrect.

The standard run also provides a calibration curve for the column. The retention times of the standard proteins are plotted against the log of the molecular weight. This calibration curve is used to estimate the molecular weight of the sample peaks. The calibration curve is valid only for the specific column and mobile phase used to generate it. A change in the mobile phase or a change in the column requires a new calibration curve.

Interpret the Chromatogram with a Decision Tree

The chromatogram from a size-exclusion run is interpreted by a decision tree that connects the observed peaks to the aggregate distribution. The first decision is whether a peak appears at the void volume. If a void peak is present, the sample contains aggregates larger than the upper limit of the column. The size of these aggregates cannot be determined on this column. The next decision is whether the monomer peak is present and whether it is resolved from the dimer peak. If the monomer and dimer are resolved, the area under each peak is used to calculate the relative amount of each species. If the monomer and dimer are not resolved, the column is not appropriate for this sample.

The decision tree also includes the possibility of a peak that elutes later than the monomer. A late-eluting peak can indicate a non-specific interaction between the protein and the resin. This interaction can be caused by the protein being positively charged and the resin being negatively charged. The addition of a salt to the mobile phase can suppress this interaction. If the late-eluting peak persists after the salt addition, the protein may be partially unfolded and have a larger hydrodynamic volume than the native state.

The decision tree is a practical tool for interpreting the chromatogram. It is not a substitute for a detailed analysis, but it provides a structured way to identify the most likely cause of an unexpected peak. The decision tree should be documented in the laboratory notebook and used for every run.

Record the Method Performance Metrics

The performance of a size-exclusion method is measured by a set of metrics that are recorded for each run. The first metric is the retention time of the monomer peak. This value should be consistent between runs. A change in the retention time can indicate a change in the column or a change in the mobile phase. The second metric is the resolution between the monomer and the dimer peaks. This value is calculated from the difference in retention times divided by the average peak width. A resolution of 1.0 or higher is generally considered acceptable for a quantitative assay.

The third metric is the recovery of the protein from the column. The recovery is calculated as the total peak area of the sample divided by the total peak area of the same sample injected without the column. A recovery below 80% indicates that the protein is being retained on the column or that the protein is aggregating during the run. The fourth metric is the back pressure of the column. An increase in the back pressure can indicate a clogged column or a change in the mobile phase.

These metrics are recorded in a logbook or a spreadsheet. The logbook should include the date, the column type, the mobile phase composition, the flow rate, the sample volume, the detection wavelength, and the metrics. The logbook is used to monitor the performance of the column over time. A change in the metrics can indicate that the column needs to be cleaned or replaced.

Troubleshooting a Failed Separation

A common failure pattern is a single broad peak where the monomer and dimer are expected to be resolved. This can be caused by a column with a fractionation range that is too narrow for the aggregate size. The solution is to select a column with a wider fractionation range. A second common failure pattern is a peak at the void volume that is not present in the sample before injection. This can be caused by the protein aggregating during the run. The solution is to change the mobile phase to a condition that stabilizes the protein.

A third common failure pattern is a peak that elutes later than the monomer. This can be caused by a non-specific interaction with the column. The solution is to increase the ionic strength of the mobile phase or to add a small amount of a solvent. A fourth common failure pattern is a decrease in the recovery over time. This can be caused by the column becoming contaminated. The solution is to clean the column according to the manufacturer's instructions.

A fifth common failure pattern is a change in the retention time of the monomer peak between runs. This can be caused by a change in the mobile phase composition or a change in the column temperature. The solution is to verify the mobile phase composition and to control the column temperature. A sixth common failure pattern is a peak that is not reproducible between runs. This can be caused by a sample that is not stable or by a column that is not performing correctly. The solution is to prepare a fresh sample and to verify the column with a standard.

Professional Escalation Criteria

If the troubleshooting steps do not resolve the separation, the method should be escalated to a specialist. The escalation criteria are specific and observable. The first criterion is a resolution below 1.0 between the monomer and the dimer after testing two different columns. The second criterion is a recovery below 80% after changing the mobile phase. The third criterion is a backpressure that increases by more than 20% over a single run. The fourth criterion is a void peak that appears in the sample but not in the buffer blank.

The specialist can help to identify the cause of the failure. The specialist may recommend a different column chemistry, a different mobile phase, or a different detection method. The specialist may also recommend an orthogonal method, such as dynamic light scattering or mass spectrometry, to confirm the size of the aggregate. The escalation is a formal process that is documented in the laboratory records.

Frequently Asked Questions

What is the difference between size-exclusion chromatography and other types of chromatography?

Size-exclusion chromatography separates molecules based on their size, while other types of chromatography separate molecules based on their charge, hydrophobicity, or affinity for a specific ligand. Size-exclusion chromatography is a non-interactive method, which means that the molecules are not bound to the column.

How do I choose a column for size-exclusion chromatography?

The choice of column depends on the molecular weight of the protein and the size of the aggregates you want to detect. The fractionation range of the column should cover the size of the molecules you want to separate. The particle size of the resin and the length of the column also affect the resolution.

What is the mobile phase in size-exclusion chromatography?

The mobile phase is the buffer that carries the sample through the column. The mobile phase should be compatible with the protein and should prevent non-specific interactions. The pH and the ionic strength of the mobile phase are important for the stability of the protein.

How do I prepare a sample for size-exclusion chromatography?

The sample should be free of particulate matter and large aggregates. The sample should be centrifuged or filtered before analysis. The sample should be in a buffer that is compatible with the mobile phase.

How do I interpret the results of a size-exclusion chromatography experiment?

The retention time of a peak is related to the size of the molecule. The retention time can be compared to a calibration curve to estimate the molecular weight of the protein. The area under the peak can be used to estimate the relative amount of the protein.

What are the limitations of size-exclusion chromatography?

Size-exclusion chromatography cannot distinguish between a protein that is larger and a protein that is elongated. The method is also not able to detect the presence of a protein that is not in the fractionation range of the column. The results should be confirmed with an independent method.

How can I prevent protein aggregation during size-exclusion chromatography?

Protein aggregation can be prevented by using a mobile phase that is compatible with the protein. The addition of a stabilizing agent can also help. The sample should be prepared to avoid the formation of aggregates.

What is the role of the column in size-exclusion chromatography?

The column is the core of the size-exclusion chromatography system. The column contains the resin that separates the molecules based on their size. The column must be selected and maintained to ensure the accuracy of the results.

Using the Evidence

Source	Best use in this topic	Important limitation
Molecular Biology and Laboratory Methods	official guidance	Check the linked page for current local requirements
Biosafety in Microbiological and Biomedical Laboratories	official guidance	Check the linked page for current local requirements
NIH Guidelines for Recombinant or Synthetic Nucleic Acid Molecules	official guidance	Check the linked page for current local requirements

Related Molecular Biology Guides

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.
Characterization of Proteins by Size-Exclusion Chromatography Coupled to Multi-Angle Light Scattering (SEC-MALS).. Journal of visualized experiments : JoVE, 2019.
Interlaced Size Exclusion Chromatography for faster protein analysis.. European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V, 2018.
Theory and practice of size exclusion chromatography for the analysis of protein aggregates.. Journal of pharmaceutical and biomedical analysis, 2014.
Aggregation analysis of pharmaceutical human immunoglobulin preparations using size-exclusion chromatography and analytical ultracentrifugation sedimentation velocity.. Journal of bioscience and bioengineering, 2013.
Micro-flow size-exclusion chromatography for enhanced native mass spectrometry of proteins and protein complexes.. Analytica chimica acta, 2023.

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