Apply flow cytometry to detect brain derived microparticles from mice suffering traumatic brain injuries

Objective To explore the determination method for concentration of brain derived microparticles (BDMP) with flow cytometry and to investigate the stability and the reliability of it. To evaluate the difference between the concentrations of BDMP in mice brain before and after trauma. Methods By applying flow cytometry detect concentration of 3copies of fluorescent particles every 2 hours, determinating 5times continuously, calculating intra-day relative standard deviation (abbreviation: intra-day RSD); Using Flow cytometry test the concentration of other 3 copies of fluorescent particles every 24 hours, determinating 5d continuously, calculating inter-day relative standard deviation (abbreviation: inter-day RSD), evaluating reliability of the flow cytometry according to intra-and inter-day RSD; We extract BDMP from mice suffering traumatic brain injury, by using flow cytometry to detect the concentration. Results The results showed that intra-day RSD of 3copies of fluorescent particles are 8.4%, 5.4% and 3.7% respectively, and the average value is 5.8%; inter-day RSD of 3copies of fluorescent particles are 4.7%, 5.8% and 3.2% respectively, and the average value is 4.6%. The results conform to the "Chinese pharmacopoeia" regulation that biological samples relative standard deviation should be less than 15.0%. Application of flow cytometry test results show that the total number of BDMP in the brain tissue from mice suffering traumatic brain injury is 340 519.67±103 043.94, whereas the total number of BDMP in the brain tissue from healthy miceis 137 358.17±40 358.66. The number of traumatic group was obviously higher than that of healthy group (P=0.024). Conclusion Application of flow cytometry to detect quantitatively BDMP is reliable and stable. It was confirmed that brain tissue after TBI could promote produce more BDMP. Key words: Brain derived microparticles; Flow cytometry; Traumatic brain injury