Flow cytometric enumeration of colonies for in vitro chemotherapeutic drug evaluation

Abstract

The percentage of 50–100 μ colonies formed by LX‐T cells in medium containing agarose was determined microscopically, and this value was compared with the percentage determined by a flow cytometric method based on the forward and 90° light scatter of the colonies. As assessed by both in vitro methods, LX‐T cells exposed to chemotherapeutic agents formed fewer colonies as the drug concentration increased. However, flow cytometric analysis indicated that a change in the number of colonies formed was a consequence of changing chemotherapeutic drug concentration, whereas microscopic colony counting did not always detect the corresponding change in colony number. These experiments demonstrate that measurement of a drug's chemotherapeutic potential by flow cytometric counting of colonies is an alternative to the enumeration of colonies microscopically. Copyright © 1989 Wiley‐Liss, Inc.