Recombinant Antigens: Methods for Determining Protein Quality
There are many variables to consider when producing recombinant proteins, and more specifically recombinant antigens. These variables include construct design, affinity tags, expression system, purification scheme, formulation, and characterization. Here we will focus on methods for determining protein quality.
There are several methods available for determining protein quality prior to immunization. SDS-PAGE combined with protein gel staining is useful for visualizing the purity of a recombinant antigen preparation. In addition, comparing reduced and non-reduced gel samples can indicate if disulfide-linked aggregates are present. Analytical HPLC-SEC is another technique to assess the purity of a recombinant antigen sample, as well as its aggregation state under native conditions. Analyzing samples pre- and post-freeze/thaw can identify any risks for aggregation when thawing the recombinant antigen prior to immunizations. Finally, the LAL assay is used to quantitate the endotoxin present in a sample, to ensure that the levels are low enough to avoid pyrogenicity during the immunization process. All of these methods are reliable quality control measures for recombinant antigens to be used for antibody production and other drug discovery applications.
This will conclude our informational blog series regarding recombinant antigens. Below are links to the previous posts if you would like more information.
- Part 1 – Recombinant Antigens: An Introduction
- Part 2 – Recombinant Antigens: Selecting an Expression System
- Part 3 – Recombinant Antigens: Affinity Tags
- Part 4 – Recombinant Antigens: Long-term Storage
Contact Proteos today to find the right expression system for your drug discovery research project. We will guide you through the process and design a custom quotation that fits your specific project needs.