Serological Identifications of Cells in Culture

It is of great importance that cell species could be identified by serological as well as by other procedures with the use of biology microscopes. Fluorescein-labeled antibody is used for species identification of animal cells. Cells cultivated in vitro are readily identified with regard to their species of origin by the immunofluorescence method. Once labeled antisera have been prepared against cells of different species, the method is simple to perform. An added advantage of this procedure is the detection of very small numbers of cells of a different species in a much larger cell population.

The Karyology of Cells in Culture

The chromosome constitution of cells in vitro has been one of the most useful criteria for monitoring cell populations. In a number of cases, contamination of one culture with another was detected by karyological analysis. When the chromosomal features of the two cell cultures are very different, even casual inspection through biology microscopes will suffice. It is well known that cell cultures in vitro frequently change their chromosomal constitutions. Karyological analysis is useful for monitoring the normalcy of the cell populations under consideration. In all cytological preparations of animal cells, regardless of the methods used, there is a certain proportion of ruptured cells, visible under biology microscopes. When one tries to determine the diploid number, metaphases losing or gaining one or more chromosomes as artifacts are not formidable obstacles since counts of 20 to 30 cells would invariably reveal the predominant number. The modal number is the real number. An ideogram is an idealized karyotype or a statistically representative karyotype. An ideogram must be arrived at by the normalization of many karyotypes.