ObjectiveTo develop a method to quantitatively determine the microparticles (MP) from different sources in plasma by nine-color flow cytometry. MethodsAnnexin-V and 8 antibodies including CD235a, CD41a, CD45, CD34, CD66b, CD20, CD3 and CD14 were used to establish nine-color flow cytometric panel.Platelet poor plasma samples were single-stained and stained with 1 of 8 antibodies lacking respectively, and then we determined the detector voltages and compensations.From December 2014 to January 2015, we detected and analyzed 10 plasma samples from normal adults, and repeatability test and dilution tests were done. ResultsIn staining lacking 1 of 8 antibodies, the percentage of positive MP populations change was all less than 15% based on the population number in single-stained experiment.In dilution tests, there were good linear correlations between MPs from platelets and erythrocytes.In repeatability test, the coefficient of variation of MP from erythrocytes, platelets and granulocytes was all less than 10%.In the platelet poor plasma samples from normal adults, MP from platelets, erythrocytes, endotheliocytes, monocytes, granulocytes, B and T lymphocytes could be detected, and the average concentration of them were respectively 132.6/μL[(60.6-288.9)/μL], 35.4/μL[(22.0-99.7)/μL], 21.6/μL[(3.3-45.5)/μL], 13.9/μL[(7.3-35.1)/μL], 60.0/μL[(22.5-101.2)/μL], 21.9/μL[(6.0-33.4)/μL]and 1.2/μL[(0.7-2.8)/μL]. ConclusionsQuantitatively determining MP from different sources in plasma by nine-color flow cytometry has been successfully developed.This method is simple and fast, and can be applied in clinical detection.