Residual CHO DNA Detection qPCR Kit-100 reactions

The Residual CHO DNA Detection qPCR Kit is designed for the sensitive detection of trace CHO (Chinese Hamster Ovary) DNA in a sample using quantitative PCR (polymerase chain reaction). By using a specific primer and probe set that targets the Alu-equivalent repeats in CHO, this kit can achieve a detection limit as low as 1 fg/µl while minimizing background noise. Each kit provides enough 2x qPCR Master Mix (no dye) for 25 or 100 reactions and includes a positive control, dilution buffer, and ROX reference dye for generating reliable standard curves. Figure 1. Principle of Probe-Based qPCR. Detection utilizes a 6-FAM-labeled probe paired with Black Hole Quencher-1 (BHQ-1). (A) In the intact probe, fluorescence is quenched via Förster resonance energy transfer (FRET). (B) During the extension phase, the 5'-3' nuclease activity of Taq polymerase cleaves the probe, separating the 6-FAM fluorophore from the quencher to generate a fluorescent signal. The absorbance and emission maxima of 6-FAM are 495 nm and 520 nm, respectively. The manufacture of biological drugs, including vaccines, antibodies, and recombinant proteins, is regulated by agencies such as the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) to ensure that biopharmaceutical products do not contain harmful impurities. Most biologics are prepared using host cell systems such as human cells, insect cells, or bacterial cells, and carry-over of host cell DNA must be kept to a minimum as it could compromise patient safety. Therefore, manufacturers must ensure that the amount of residual host cell DNA is kept within safety levels defined by regulatory agencies. While specific requirements may vary depending on the host cell type and route of administration, these agencies generally recommend a maximum limit of 10 ng of host cell DNA per drug dose. To facilitate quality control, the Residual CHO DNA Detection qPCR Kit enables the detection of CHO DNA at concentrations as low as 1 fg/µl, with no cross-reactivity to human or bacterial DNA. This specificity is achieved by targeting the CHO Alu-equivalent sequence, a conserved and highly repetitive DNA element found in the CHO genome. Due to the abundance of these Alu-like elements, the primers and probe designed against a consensus sequence ensure high sensitivity and specificity for Chinese hamster DNA.