QUANTITATION OF THE NUMBER OF CELLS WITHIN TUMOR COLONIES IN SEMISOLID MEDIUM AND THEIR GROWTH AS OBLATE SPHEROIDS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (1) , 271-277
Abstract
Colonies formed in agar from 38 [human] tumor cell samples of diverse histological origin were stained, removed with a micropipet and the number of cells were directly counted. The number of cells within colonies increased geometrically with colony diameter and inversely with the size of the cells within the colonies. The relationship can be described using linear regression: [ln(number of cells/colony) = 0.87 - 2.80 ln(colony cell diameter) + 2.38 ln(colony diameter)] which gave an R2 of 0.92. Measurements of colonies in agar showed that they grew as oblate spheroids rather than spheroids. In an average sample, 60-.mu.m-diameter colonies contained 8-10 cells; the range for the 38 samples was 1.2-48.5. These results precisely define colonies in terms of cell number. They allow calculation of the total number of cells formed from clonogenic cells, a more complete estimate of proliferation than conventional cloning efficiencies which only measure initial proliferation. Because of the dependence on the size of the colony cells, if colonies are defined only by a specific diameter then they do not contain similar numbers of cells. Calculations which assume spherical colonies, rather than the oblate spheroid shape, greatly overestimate the number of cells within colonies. The accuracy of quantitation in the clonogenic system was increased and the interpretation of the proliferation of clonogenic tumor cells was improved.

This publication has 0 references indexed in Scilit: