Identification of Cell Lines

Abstract

Discrimination between and identification of cell lines are important in order to avoid confusion due to mislabeling and accidental cellular contamination. Cell morphology is not a reliable criterion for the identification of cells, because the shape of a cell changes easily with different culture conditions, and a cell population usually consists of various-shaped cells, even in a cloned cell line. Chromosome analysis can be used to discriminate between and identify cell lines; however, lepidopteran cell lines have numerous small chromosomes and this makes determination of the karyotype difficult in these cases. Isozyme pattern analysis is also useful in the identification of cell lines, but isozyme pattern analysis does not clearly distinguish cell lines derived from taxonomically close species, or cell lines derived from the same species. A reliable method for discriminating cell lines is the recently developed restriction fragment length polymorphism (RFLP). However, this method has some drawbacks: radioisotopes, a large number of cells, and southern hybridization are needed in RFLP, and the procedure itself is not simple. More recently, a polymerase chain reaction (PCR) method for the study of phylogeny came into use. This technique is a good tool for the discrimination of cell lines. Furthermore, a method of random amplified polymorphic DNA (RAPD)-PCR has been developed. Because gene analyses of insect cell lines are scarce, a method of RAPD-PCR using appropriate short single primers seems to be most practical.