Probability paper analysis of flow cytofluorometric measurements of cellular deoxyribonucleic acid content

A graphic analysis of cellular deoxyribonucleic acid (DNA) histograms obtained by flow cytofluorometry is described. This technique utilizes probability paper that graphs data in cumulative percentile form. From this graphic representation, individual normal distributions contributing to the histogram may be isolated and statistically describe. G0G1 and G2M distributions are independently described and S phase is fit to 1--5 overlapping normal distributions as dictated by the analysis results. This technique offers several advantages, including relatively simple mathematical calculations and few assumptions or restraints placed on the analysis. It has proved to be useful in analyzing proliferating and nonproliferating populations as well as distributions with unusual findings such as debris or aberrant DNA contents.