Colony-forming ability, determination

Colony forming ability of the fetal liver cells was determined in the medium comprised 1.3% methylcellulose, 4.0 mM glutamine, 10 U/ml penicillin/-streptomycin, 100 U/ml GM-CSF, 100 U/ml IL-3, 50 ng/ml stem cell factor and 10 U/ml erythropoietin in IMDM. An aliquot of 10 cells was transferred to a 35 mm sterile plastic Petri dish and incubated at 37 C in a fully humidified atmosphere of 5% CO2 in air. The final colony count was performed on day 14 of culture, the colony types being defined by general morphological criteria. 

Fig. 2. Time course of PLDR in MNNG-treated cells. Quiescent cells were treated with 68 pM MNNG for 20 min and cell survival was determined by colony-forming ability at the indicated times, relative to untreated control cells. (A) Experiment 1, ( ) experiment 2...

FIGURE 4. Percentage survival of the colony-forming ability of strains of diploid human fibroblasts as a function of the dose of UV radiation given. See Section 2.2 for details on determining UV cytotoxicity. Taken from Maher et ai with permission. 

Luster et al., 1992a, b). Specifically, the use of either a humoral response assay for plaque-forming colonies (PFC response) or determination of surface marker expression in combination with almost any other parameter significantly increased the ability to predict immunotoxicity when compared to the predictivity of any assay alone. 

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