Methods for Detecting Residual Host Proteins

The method of testing for host protein residues is to ensure the purity and safety of biopharmaceuticals. In the production process of biological drugs, host cell proteins (HCPs) produced by the production cells may remain in the final drug product, and the presence of these proteins may affect the safety and effectiveness of the drug. Therefore, pharmaceutical companies need to adopt effective methods to detect and quantify the residues of these host proteins.

 

ELISA Method

One of the common methods for detecting host protein residues is the Enzyme-Linked Immunosorbent Assay (ELISA). This is an immunological detection method that uses specific antibodies to detect target proteins. The advantage is its high sensitivity, which can be used for quantitative detection. However, the disadvantage of the ELISA method is that it requires antibodies against specific HCPs and may produce false-positive or false-negative results for some HCPs.

 

2D-PAGE-MS Method

In addition, Two-Dimensional Polyacrylamide Gel Electrophoresis-Mass Spectrometry (2D-PAGE-MS) is also a common method for detecting host protein residues. 2D-PAGE-MS is a method based on the differences in protein molecular weight and isoelectric point for separation, and it can detect a wider range of HCPs. Compared with the ELISA method, 2D-PAGE-MS can detect a more comprehensive protein spectrum, but it is more complex to operate and requires a higher level of technical skill.

 

Peptide Mapping Method

Peptide mapping is another method to detect host protein residues. Through protein proteolysis, high-performance liquid chromatography, mass spectrometry, and other steps, a peptide map of the protein is obtained, and then the protein is structurally identified and quantitatively analyzed. The advantage of this method is its high accuracy, which is suitable for the analysis of complex samples, but the operation steps are complex, and it requires a high level of technical skill and professional equipment.

 

The choice of method for testing host protein residues depends on many factors, including the required sensitivity and accuracy, the complexity of the sample, and the available equipment and technical level. Currently, there is no single method that can be applied in all cases, so it is usually necessary to combine multiple methods to ensure the quality and safety of the final drug product.