Expression of recombinant viral vectors and vaccines in mammalian cell culture is a cost-effective method for production of commercial quantities of gene therapy and vaccine biologics. The manufacturing and purification process of these products leaves the potential for contamination by endonuclease enzyme often used to remove endogenous host cell DNA and RNA, as well as unincorporated plasmid DNA from viral vector production. It is desirable to reduce endonuclease contamination to the lowest levels practical.

Cygnus EndonucleaseGTP® ELISA kit is based on antibodies generated and affinity purified against a genetically engineered endonuclease from Serratia marcescens. With a detection limit of ~60 pg/ml, it is a sensitive and specific method to aid in purification process development, process control, routine quality control and product release testing. The kit uses a simple simultaneous protocol where samples containing endonuclease are reacted simultaneously with a HRP-labeled anti-endonuclease detection antibody in microtiter strips coated with an affinity purified capture anti-endonuclease antibody.

The EndonucleaseGTP® ELISA Kit contains all components to evaluate the presence of endonuclease impurities in 96 samples, including a set of calibrated endonuclease standards. It is suitable for the detection of genetically engineered endonucleases such as Benzonase Nuclease and DENARASE.

*Benzonase Nuclease is a registered trademark of Merck KGaA DENARASE is a registered trademark of c-LEcta.

The manufacturing and purification process of these products leaves the potential for impurities by host cell proteins (HCPs) from HEK 293 cells. HCP impurities can result in adverse toxic or immunological reactions and thus it is desirable to reduce these impurities to the lowest levels practical.

The polyclonal antibodies used in this kit have been generated against and affinity-purified using a mild lysate of HEK 293 cells to obtain HCPs typically encountered in initial product recovery steps. This kit can be used as a process development tool to monitor the optimal removal of host cell impurities as well as in routine final product release testing when comprehensively characterized using samples from your process. Antibody Affinity Extraction (AAE™) was used to determine reactivity to individual HCPs in a mild lysate of HEK 293. AAE indicated reactivity to ~74% of the individual 2-D PAGE fractionated spots presumed to be HCP. The F650S kit uses a new broadly-reactive antibody exceeding the reactivity of the previous F650R antibody. In addition, F650S kit has increased sensitivity (LOD 0.2 ng/mL; LOQ 1 ng/mL), a shorter Detection Ab and Sample/ Standard incubation time (1.5 h) and enhanced stability.