| Abstract: | Colonies of Chinese hamster ovary (CHO) cells growing on agar exhibit changes in colony morphology and size in response to extremely low doses of hormones and growth factors. Computer-aided densitometric scanning of photographs of these colonies allows the quantitative measurement of these morphological changes. Correlation of these changes with dosage for a variety of growth effectors is a sensitive assay for the effects of these factors, both alone and in combination, and should be useful in comparing effects of agents with similar biological activities and in the search for variant cell types with altered responsiveness. Cells growing attached to solid substrates are often responsive to these low dosages and do not seem to mimic in vivo growth effector phenomena as well as colonies growing in three dimensions on agar. |
