Growth inhibitory effect of mouse serum on eukaryotic cells in a micro assay

Inhibition of cell growth by B6D2F1 (C57Bl/6 X DBA/2) mouse serum in tissue culture wells confirming previous findings in the soft agar tumour colony assay is reported. The assay was time saving, more sensitive, and the amount of mouse serum used could in each experiment be reduced by 95%. In addition non-neoplastic cells ordinarily not forming colonies in the soft agar assay could be tested. Such cells were less sensitive to the growth inhibitory effect when compared to neoplastic cells.