A monoclonal antibody specific for snRNPs U1 and U2

A monoclonal antibody (D-5) is described which selectively precipitates snRNPs U1 and U2. The antibody was derived from a mouse immunized with extracts from chick embryonic nuclei. By immunoblotting on either total proteins from purified snRNPs U1-U6, U2-U6 or U1 only, we could demonstrate that the monoclonal antibody cross-reacts with the U1 RNP specific polypeptide A and the U2 RNP specific polypeptide B", thereby establishing that the two snRNP proteins share at least one epitope. D-5 precipitates snRNPs U1 and U2 from a variety of species, including man, chicken, mouse, rat kangaroo and Xenopus laevis. It will thus be a useful tool for studying structure function relationships of the two snRNP species in different cell systems.