Protein A purification medium is widely used in the production process of antibody drugs because of its specific adsorption to most antibodies. Protein A is bound to the purification medium through covalent bonds, but Protein A has a certain probability of shedding during the purification process and remains. Protein A ELISA Kit is an ELISA kit that can accurately quantify residual Protein A in samples and can be used for process optimization during antibody purification, evaluation of critical quality parameters, and detection of Protein A residues in intermediate and final products.

This kit applies the experimental principle of double antibody sandwich enzyme-linked immunosorbent assay (ELISA) to detect the residue of Protein A. Protein A standard (36716-B) and the sample to be tested are added to Protein A capture microwell strip (36716-A) pre-coated with anti-Protein A antibody, then diluted Biotin-labeled Protein A detection antibody (36716-C), and finally Streptavidin-HRP (SA-HRP) (36716-D) are added to form antibody + antigen + antibody-Biotin + SA-HRP complex. After washing the plate, add TMB color development solution (36716-F) to develop color. TMB was converted from colorless to blue under the catalysis of HRP enzyme and finally to yellow under the action of stop solution (36716-G). The depth of yellow color is positively correlated with the amount of Protein A detected in the sample.

The detection range of this kit is 15.625~1000 pg/mL; the lower detection limit is 5.6 pg/mL.

Validation Report

Feature

• Highly sensitive: Detecting as little as 5.6 pg/mL of Protein A residuals in in-process and final biological samples.
• Ensures accuracy: The Protein A residuals can be accurately detected with a recovery of 75%-125%.
• Specificity: Specific detection of Protein A without interference from other exogenous proteins.
• Stable: The difference between lot-to-lot is low, the kit property is not impacted under 37℃ for 7 days.
• Easy signal collection: Using Biotin-Streptavidin system, the signal can be stably enlarged.

Application

Residual Protein A test in biological products

Specification

Product Performance

Components

Storage

This product should be stored at 2°C ~8°C. Unopened product is valid for one year.

^*Upon receipt of the kit, please check whether all components are complete and immediately store them in corresponding condition.

Figures

Specificity Demonstration

The E brand Protein A ELISA Kit and Yeasen's Protein A ELISA Kit were used to detect 4 different types of Protein A, 3 of which are standards in the kit and the other one is a major Protein A ligand in the market. Yeasen's product is able to accurately detect the Protein A standards in the major Protein A ELISA kits and has comparable or even better detection ability for Protein A ligands in the major Protein A packages in antibody production than E brand. Yeasen products can accurately detect Protein A standards in some of the major Protein A ELISA kits in the market, and compared to Brand E, Yeasen products have comparable or even better detection ability for Protein A ligands in the major Protein A fillers used in antibody production.

Table 1. The specificity of Yeasen Protein A ELISA kit was shown in the table above

Precision Display

A) Repeatability

B) Intermediate precision

Table 2. The precision of Protein A ELISA was assayed as the above scheme

10 duplicated were tested at 3 concentrations on the standard curve, and all the CV% were lower than 10% (Table 1A). 3 lot of Protein A ELISA kits were tested and the CV% were lower than 15% (Table 1B).

Accuracy Validation

Different concentrations of Protein A were added to the 34 μg/mL hIgG authentic samples, and Protein A was detected in the unspiked samples at the same time. The recoveries of the spiked samples were in the range of 90%~110% for the different concentrations of Protein A in the samples containing hIgG.

Table 3. Accuracy Validation

Documents:

Safety Data Sheet

36716_MSDS_HB20250310_EN.PDF

Manuals

36716_Manual_Ver.EN20250310.pdf