In this study, we used Sartorius Real-time PCR kits for the rapid detection of bacteria, fungi, and mycoplasma to establish that these assays can detect microbial contaminants, even in the presence of high cell backgrounds, ranging from 10 to 40 million cells per milliliter (cells/mL). We observed that the cell density limit and assay robustness depend on cell types and media compositions. The detection limits for bacteria, fungi, and mycoplasma in Jurkat cells, HPBMC and CHO cells varies between 10 and 25 x 10⁶ cells/mL.
 

This study clearly demonstrates that Sartorius Microsart^® ATMP kits tolerate higher cell density, still reaching the required sensitivity criteria (≤ 99 CFU, or colony forming units, for bacteria and fungi and ≤ 10 CFU for mycoplasma). The study also demonstrates the capability of Microsart^® ATMP kits to sensitively detect microorganisms, even in the presence of high density cell cultures, and thus contributes to risk-reduction and patient safety of cell therapy products.