Image analysis for the automated estimation of clonal growth and its application to the growth of smooth muscle cells

Abstract. Image analysis was used for the automated measurement of colony frequency ( f ) and colony diameter ( d ) in cultures of smooth muscle cells, Initial studies with the inverted microscope showed that number of cells ( N ) in a colony varied directly with d : log N = 1.98 log d - 3.469 Image analysis generated the complement of a cumulative distribution for f as a function of d . The number of cells in each segment of the distribution function was calculated by multiplying f and the average N for the segment. These data were displayed as a cumulative distribution function. The total number of colonies ( f_T ) and the total number of cells ( N_T ) were used to calculate the average colony size ( N_A ). Population doublings (PD) were then expressed as log₂ N_A . Image analysis confirmed previous studies in which colonies were sized and counted with an inverted microscope. Thus, image analysis is a rapid and automated technique for the measurement of clonal growth.