High viscosity sheath reagent for flow cytometry

摘要

A flow cytometer for the analysis of large particles or small multicellular organisms may experience unstable flow because of the large diameter of the flow chamber. The use of a sheath fluid or a sheath and sample with addition of a viscosity-increasing agent to give a viscosity higher than that of water ensures that flow in the pre-analysis section will be fully developed laminar flow, and that the flow in the analysis section will be laminar. This allows accurate analysis and sorting of large particles or analysis and sorting of smaller particles at an increased rate of speed. Water-soluble polymers are preferred because they increase fluid velocity with negligible osmotic effects. A 0.9 weight % solution of polyvinyl pyrollidone with an average molecular weight of 1.3 million is particularly effective. Use of viscosity-increasing agents that cause minimal increases in surface tension of the fluid is also preferred.