The original depositor information (PubMed: 4316953) reports that the MRC-5 cells are capable of 42 to 46 population doublings (PDLs) before the onset of senescence. PDL is different from passage number. Refer to the Certificate of Analysis on the ATCC item website for each lot of cells to get the information on PDL for this cell line. It is very important to calculate the PDLs for this normal diploid human cell line during routine sub-culturing. This will ensure that the cells are minimally sub-cultured and frozen as quickly as possible so that they do not start to senesce.
The passage number refers to the number of times the cells in the culture have been sub-cultured, often without consideration of the inoculation densities or recoveries involved. The population doubling level (PDL) refers to the total number of times the cells in the population have doubled since their primary isolation in vitro. This is usually an estimate rounded off to the nearest whole number.
A formula to use for the calculation of population doublings is as follows: PDL = 3.32 (log Xe – log Xb) + S, where Xb = the cell number at the beginning of the incubation time, Xe = the cell number at the end of the incubation time, and S is the starting PDL of the inoculum used to initiate the subculture being quantitated.
|Date Created||05/19/2014 09:35 AM
|Date Updated||05/19/2014 09:41 AM