Identification of the SS-A/Ro intracellular antigen with autoimmune sera

Autoantibodies to SS-A/Ro antigen have been described in the sera of certain patients with Sjögren's syndrome, systemic lupus erythematosus and in neonates with lupus and/or congenital heart block. SS-A/Ro is a trypsin-sensitive intracellular antigen which appears to be associated with another intracellular antigen SS-B/La in tissue extracts. This study describes a simple method of separation of SS-A/Ro and SS-B/La antigenic activity by differential salt elution in polybuffer ion exchange chromatography. The partially purified SS-A/Ro antigen was separated by polyacrylamide gel electrophoresis under non-denaturing conditions and identified by Western blot analysis as a single polypeptide of 61,000 Da. The pI of SS-A/Ro antigen was 4.67. The partially purified SS-A/Ro antigen derived from gel electrophoresis could be adapted to an enzyme linked immunosorbent assay (ELISA) for the detection of antibody.

RNA recombination: --introducing poly(A) into Q beta phage

Poly(A) molecule is inserted between two Q beta RNA molecules which have been partially degraded, one from the 3'-end and another from the 5'-end. E. coli HfrH is infected with these mosaic RNA molecules and a few recombined phages carrying poly(A) are obtained. Analysis of the RNA of 907 phage (one of these recombination phages) shows that the chain length of the poly(A) it contained is about 40.