A simple and quick method to concentrate MSCV retrovirus.

Retroviral-mediated gene transfer is widely used to express proteins in hematopoietic cells for the analysis of their effects on blood cell proliferation, differentiation, and biological function. The efficiency of gene transfer depends on the concentration of retrovirus in cell culture medium during infection. Here, we report one simple and quick method to increase titers of retrovirus. Centrifugation of murine stem cell virus (MSCV) in either microcentrifuge or high-speed centrifuge for only 1 h can significantly concentrate retrovirus at the bottom of the tube. The resuspended retrovirus can be used effectively to infect target cells in gene transfer experiments.