How to Cleaning of Protein Residues in HPLC Column
Cleaning protein residues from an High-Performance Liquid Chromatography (HPLC) column is a critical step to maintain the column’s performance and ensure accurate and reproducible results. Here are general steps you can follow for cleaning an HPLC column that has been exposed to protein samples:
- Initial Rinse:
- Flush the column with a compatible solvent (usually the mobile phase or a similar solvent) to remove loosely bound proteins. This step helps in removing the bulk of contaminants before more aggressive cleaning.
- Organic Solvent Wash:
- Use an organic solvent (such as acetonitrile or methanol) to wash the column. This helps to break down and remove hydrophobic contaminants. Run the organic solvent through the column for an extended period to ensure effective cleaning.
- Reverse-Phase Solvent Gradient:
- Employ a reverse-phase solvent gradient, starting with a low percentage of organic solvent and gradually increasing it. This can help remove hydrophobic residues and contaminants.
- pH Adjustment:
- Adjust the pH of the mobile phase to influence the ionization state of residues. For example, using a lower pH (acidic conditions) can help in dissociating and removing basic residues.
- Buffer Wash:
- If the protein residues are not effectively removed with organic solvents, use a buffer wash. Choose a buffer that is compatible with both the column material and the proteins you are dealing with. Run the buffer through the column for an extended time.
- Detergent Wash:
- In some cases, using a mild detergent in the mobile phase can help remove protein residues. Ensure that the detergent is compatible with your HPLC system and does not leave residues that could interfere with future analyses.
- High-Pressure Flushing:
- Perform high-pressure flushing by increasing the flow rate for a brief period. This can help dislodge and flush out any remaining particles or residues.
- Flush with Water:
- Follow the organic solvent and buffer washes with a thorough flush using water. This helps remove any remaining contaminants and ensures that the column is ready for subsequent use.
- Column Regeneration:
- If the column performance is severely compromised, consider regeneration procedures recommended by the column manufacturer. This may involve more intensive cleaning procedures or regeneration solutions.
- Quality Control Check:
- After cleaning, perform a quality control check by running a standard sample through the column and monitoring the chromatogram for baseline stability and peak shape.
Always refer to the specific recommendations provided by the HPLC column manufacturer, as cleaning procedures can vary based on the column material and the nature of the contaminants. Additionally, it’s important to clean the column regularly to prevent the buildup of residues that could affect chromatographic performance.
Silica matrix HPLC columns are generally compatible, but organic polymer matrix columns may expand or contract in some solvent combinations, which will affect their chromatographic behavior.
Wash each solvent system at least 20 volumes. Because some solvent systems are highly viscous, the flushing flow rate should be adjusted accordingly to ensure that it does not exceed the pump pressure. When the solvent such as guanidine or urine is used up, the HPLC column should be flushed with at least 40 to 50 volumes of HPC water.
Surfactants such as sodium dodecyl sulfonate (SDS) and trinitrotoluene are not recommended for reversed-phase columns because of these modifications.
Compounds are bound to be firmly adsorbed on silica gel bonded phase columns and are difficult to remove. The surfactant can affect the filling surface and change it.
Nature. However, a study by a separation team showed that contaminated columns made by a team could be used with 500 mL 1% SDS.
The solution was scavenged with 1 ml/min flow rate. If we continue to use trifluoride from 5% to 95% containing 1%(v/v)
Gradient elution of acetic acid with ethyl-clear can restore the separation of the polypeptide.
