Abstract: The SCID mice、BALB/c nude mice and BALB/c mice were intraperitoneally inoculated with quantitative mixture of MHV1，MHV3，A59, JHM and euthanized on 1st，2nd，5th，8th day after inoculation. The blood and liver samples were taken,and the liver was homogenized with plastic homogenizer in a 1. 5ml microfuge tube for extracting total tissue RNA. Then, the RNA was transcribed into cDNA by using Mu-MLV re-verse transcriptase and the cDNA was amplified by PCR in same tubes.The results indicated that MHV of the blood and liver were detected on 1st day in SCID mice and BALB/c nude mice and on 5th day in BALB/c mice after inoculation.

Key words: Mouse hepatitis virus, SCID mouse, nude mouse, RT-PCR