Purification of RNA-directed DNA polymerase from mouse spleen infected with Rauscher leukemia virus

RNA-directed DNA polymerase was purified from spleens of Balb/c and NMRI mice infected with Rauscher murine leukemia virus. The method includes cell fractionation and lysis of microsomal fraction, chromtography on Sephadex G-200 and phosphocellulose. Estimation of molecular weight from the sedimentation rate of the purified enzyme in a glycerol gradient was consistent with a structure containing one polypeptide with a molecular weight of 70,000. Purified RLV DNA polymerase from spleen could transcribe purified DNA polymerase from purified virions. This simple preparation method offers a procedure for large scale preparation of the RNA-directed DNA polymerase which can be used for synthesis of DNA complementary to mRNA.