Cygnus offers 4 ELISA kits to measure CHO HCPs. Kit F015, the first kit developed more than 18 years ago, utilized a mild lysate of washed CHO cells for the immunogen as well as the for affinity purification of the antibody and for kit standards. This mild lysis procedure generated an array of HCPs similar to those found in culture media after cells have been grown to densities and viabilities similar to product harvest. Cygnus continues to support this kit as many companies have qualified it for their process. However, for first time users we suggest you first try our F550-1 3rd Generation CHO ELISA kit as it has been qualified for many products and has proven to be a broadly reactive generic kit able to detect downstream HCPs in most processes.
Kit CM015 was developed 16 years ago with the rationale that since most CHO expressed products are released into the growth media (conditioned media) an antibody and/or assay made to those HCPs found in conditioned media should be more specific than a cell lysate assay. However, the CM015 kit has been demonstrated to be more process specific and thus is not a generic kit that might be applied across most products and processes.
The F550 3rd Generation kit uses an even more reactive antibody than earlier kits and incorporates significant improvements in the assay methodology. The antibody used in this kit has been evaluated for coverage by orthogonal methods like 2D WB and a much more sensitive and specific method termed Antibody Affinity Extraction (AAE). Because AAE is >100 times more sensitive than 2D WB, AAE can be used to determine coverage to the most important HCPs, those that co-purify with your product. The F550 kit, when supported by comprehensive qualification of the ELISA itself along with data from orthogonal methods like AAE and Mass Spectrometry, has been approved for use as the lot release test in several processes. With such comprehensive data, it is often possible to obviate any need for a process-specific assay.
This CHO HCP 3rd Generation ELISA Kit, Item Number F550-1, will be replacing the current CHO HCP ELISA Kit, 3G, Item Number F550. Cygnus has manufactured, characterized, and qualified large pools of the new reagents that will replace the current lots of reagents. The new antibodies were developed and purified in the same way as the original critical reagents in the F550 Kit. The coverage of the new antibodies to the CHO HCP antigen was determined to be ~86% by Antibody Affinity Extraction which is not significantly different from the current antibody in the F550 kit. More importantly, Cygnus Technologies has demonstrated the equivalency of the new antibodies (3G-0016-1-AF) in the 3G CHO ELISA (F550-1) using a panel of CHO samples from a number of independent biomanufacturing processes.
Contact our expert technical staff to determine if the F550-1 kit is satisfactory for your product and process or if a process-specific method is needed.