Determination of red cells, nucleic acid-containing cells and platelets (RNP Determination) by a crossover analysis of emission DNA/RNA light.

We developed a new flow cytometry analysis method using a crossover analysis of emission light from intracellular DNA/RNA. Both the RNA and the DNA content in each cell were new parameters obtained by fluorescence analysis using acridine orange supravital stain. With this method, two-dimensional diagrams produced by cellular RNA concentration (CRc) and cellular DNA concentration (CDc) enabled clear separation of red cells and platelets, and the diagram (RNP Diagram) also distinguished fluorescently stained blood cells and small particles derived from background dust of the reagent. This study assessed the capability of RNP Determination concerning reticulocyte count and accurate platelet count obtained by the ratio of red cells and platelets. The distance of each event between red cell distribution and platelet distribution was sufficiently large on the diagram, and the two regions did not overlap. Both reticulocyte count and platelet count showed excellent correlation with those obtained by their respective reference methods. In conclusion, this new assay, using RNP Determination, demonstrated great potential for detecting abnormalities of red cells and platelets.