Cloning of normal and transformed cells on plastic films

Considering that the so-called 'dilution culture method' is rather inefficient and that there is never absolute certainty that a clone is uncontaminated by other cells, the author tested a variety of plastic film brands. By using plastic film the cells or clones to be isolated are removed from the vessel by cutting out a section of the plastic film and transferring it into a new vessel. The method and its pitfalls are described in detail. Fourteen brands of film were tested. Only two of them (Transilwrap polyester and Yellow Decco film) were found to serve well for W.I.-38 diploid human fetal cells. For Chinese hamster ovary cells Saran wrap and Reynolds' Brown-In-Bag could also be used but sometimes a few days of incubation were required before the cells became well spread. Other brands interfered with speading, growth or/and attachment of the cells. Two brands were found to be toxic.