The effect of tissue disaggregation methods on the clonogenicity of solid human tumor cells

The effect of mechanical, enzymatic and combined disaggregations on the same tumor tissue (n = 154) to define variables related to clonogenic efficiency (CE) of human tumor clonogenic assay (HTCA) was examined. Overall, CE was highly associated with the percentage of malignant cells in the inoculative suspensions (P less than 0.001) and the total cell concentration plated (P = 0.03). However, there was no significant correlation between CE and the disaggregation method, type of tumor, cell viability, proportion of macrophages in the inoculum, or length of incubation (10 or 20 days). In addition, a higher CE was found in some nonadherent fractions when comparing the CE of the original plating suspensions to that of their nonadherent fractions. It is concluded that mechanical disaggregation is the simplest technique for obtaining the highest yield of malignant cells, which is a decisive factor for colony growth, and that an incubation time of 10 days and 1 x 10(6) cells per plate is the best condition for the human tumor clonogenic assay.