| T1 |
0-472 |
Epistemic_statement |
denotes |
The latter can come from medium ingredients that have a biological origin, such as serum (Kniazeff, this volume) or trypsin (Hallauer et al., 1971) , can result from accidental contamination of the cultures by the technicians who handle them (Collier, 1957) , or can be introduced in association with the cells used to initiate the cultures (Hsiung, 1968) , the latter being particularly likely to occur when primary tissue cultures are used (Kalter and Heberling, 1968 ). |
