the effect of expression time ( the time between the end of the treatment period and the first exposure to selective medium ) on the frequency of benzo [ a ] pyrene ( bp ) -induced mutations at the hgprt ( hypoxanthine-guanine phosphoribosyl transferase 2.4.2.8 ) locus was examined in the cell-mediated mutation assay in which v79 chinese hamster cells are the targets and bp activation is mediated by syrian hamster embryo cells .
C1708726
locus
C0007634
cells