Fig. 3
Immunoprecipitation using radiolabeled K562 cell extracts. 35S-methionine labeled human K562 cell lysates were immunoprecipitated by patients’ IgG and resolved by electrophoresis on 8% and 12.5% gels as previously described [25]. The 12.5% gels are used to provide better resolution of lower molecular mass proteins. The case report patient (Pt) is shown with comparator human sera bearing autoantibodies to U1RNP and survival of motor neuron (SMN) complex (lane 1), or anti-Ro60 (lane 2), and a negative human serum that did not immunoprecipitate any protein (lane 3)