We provide antigen concentrates for most of our ELISA kits. These antigens are intended for use in making controls and performing Spike & Recovery experiments. Most of the HCP antigen concentrates come from crude sources such as lysate or culture media and may have been further processed or purified. Absolute quantitation of these very complex antigens mixtures is very difficult.
The potency and stability of these antigens in various dilution matrices has not been established. For these reason, an "approximate" concentration value is listed on the label. In the final analysis, it is the responsibility of the end user to determine the final concentration of these antigens under their conditions of use and relative to standards/calibrators available for the assay.