DNA image cytometry - An alternative method in osteoblast proliferation assays

OBJECTIVE: To assess whether DNA image cytometry can he used as an alternat ive method to tritiated thymidine uptake quantification in osteoblast proli feration assays. STUDY DESIGN: Proliferation of normal human osteoblasts incubated with norm al human serum at 0%, 2.5%, 5%, 10%, 20% and 40% was quantified by tritiate d thymidine uptake quantification and DNA image cytometry. RESULTS, Tritiated thymidine uptake quantification showed that normal human serum stimulated the proliferation of normal human osteoblasts and that th e degree of stimulation was directly related to the concentration of serum in the culture medium. Similar results were obtained when the DNA image cyt ometry assay was used. A highly significant linear relationship between the ranks of both methods was found (Spearman's r=1.00, P=.0253). CONCLUSION: DNA image cytometry may be a valuable alternative when the use of radioactive material is not desired and/or subsequent morphologic or imm unocytochemical characterization of cells tinder study is required.