Validation of cell density and viability assays using Cedex automated cell counter.
A method using Cedex automatic cell counter (Innovatis) to determine the cell density and viability of a whole cell-based immunotherapy product has been developed and validated for the assay performance characteristics including specificity, accuracy, precision, linearity, range, and robustness. Instrument-to-instrument variation due to intrinsic differences in handmade flow cells was also evaluated. For cell density, Cedex demonstrated acceptable specificity, accuracy and precision for cell densities ranging from 3.13x10(5) to approximately 1.0x10(7)cells/mL, with intermediate precision of about 5% relative standard deviation (RSD). However, a marked difference was observed between the two instruments studied and they therefore could not be used interchangeably without additional calibration procedures that went beyond the manufacturer's recommendation. For viability, mixing known numbers of non-viable cells with highly viable cells allowed evaluation of the specificity, accuracy and linearity of the viability determination. Acceptable levels of accuracy (95.3-106.4% recovery) and precision (RSD<5%) were demonstrated for the viability range from 50 to 100%. The instrument-to-instrument difference was less than 4.6%. The assays for both cell density and viability were sufficiently robust for assay parameters. However, the effect of certain parameters was cell line-dependent, suggesting that Cedex performance should be verified for each cell line of interest.
Huang
Li-Chun
LC
Assay Development, Cell Genesys, Inc., 500 Forbes Blvd., South San Francisco, CA 94080, USA. lhuang2006@gmail.com
Lin
Wendy
W
Yagami
Machiko
M
Tseng
Daphne
D
Miyashita-Lin
Emily
E
Singh
Nitasha
N
Lin
Andy
A
Shih
Shian-Jiun
SJ
D000704:Analysis of Variance; D002138:Calibration; D002452:Cell Count / Q000295:instrumentation* / Q000379:methods; D045744:Cell Line, Tumor; D002470:Cell Survival; D019411:Clinical Laboratory Techniques / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D015203:Reproducibility of Results