ResDetect™ Universal Protein A Quick ELISA Kit (Boiling-free)

Protein A is a cell wall protein of Staphylococcus aureus, it has a variety of specific biological characteristics. Due to its high affinity with the Fc part of certain immunoglobulins (especially IgG), it is widely used in the purification of biopharmaceuticals (such as antibodies, vaccines, etc.). However, during the purification, protein A may leach from the purification column and result in contamination of the antibody drugs prepared. Once the remaining protein A enters the human body, it will easily activate the immune response of the organism, and there is a safety risk, so there are strict regulations on the residual level of Protein A in antibody drug preparations. Therefore, the detection of residual Protein A in antibody drugs purified from Protein A purification column is a key quality control step in the production process of antibody drug preparations. The resDetect™ Universal Protein A Quick ELISA Kit (Boiling-free) can detect protein A or unnatural protein A variants within 2 hours, it is high sensitive and easy to operate because the sample processing has been changed from the original boiling method to adding denaturing reagents. The sample processing process has been shortened by one hour. Whether in upstream small-scale trials or downstream large-scale of antibody production processes, this kit can help you to accurate analysis of samples, monitor the protein A levels and ensure product quality.

The kit is developed for the detection of natural or structurally conserved recombinant forms of Protein A and a recombinant form of Protein A with very significant structural differences from natural Protein A such as MabSelect SuReTM in Bioprocess manufacturing applications. It is used as a tool to aid in optimal purification process development and in routine quality control of in-process streams as well as final product.

Unopened kit should be stored at 2°C-8°C upon receiving. Find the expiration date on the outside packaging and do not use reagents past their expiration date. The opened kit should be stored per components table. The shelf life is 30 days from the date of opening.

The resDetect™ Universal Protein A Quick ELISA Kit (Boiling-free) is used to measure the levels of protein A and protein A variants by employing a standard sandwich-ELISA format. The micro-plate in the kit has been pre-coated with anti-protein A polyclonal antibody. Firstly, the standard samples provided in kit and your samples are treated with Denaturation Buffer to dissociation of protein A and antibody, stand a few minute. Before adding standards and samples, add the Biotin-Anti-Protein A Antibody to the plate to ensure that the standard samples are neutralized by the Biotin-Anti-Protein A Antibody buffer solution and protect the pre-coated antibody on the plate. Then, add the standard samples and your samples to the plate and form Antibody-antigen (Protein A) - biotinylated antibody complex, incubate and wash the wells. Next add Horseradish peroxidase conjugated streptavidin (Streptavidin-HRP) to the plate, incubate and wash the wells to remove any unbound reactants. At last, load the tetramethylbenzidine (TMB) substrate into the wells and monitor a blue color. The reaction is stopped by the addition of a stop solution and the color turns yellow. The intensity of the absorbance can be measured at 450nm and 630nm on a microtiter plate reader. The OD Value reflects the amount of protein A.