Fig. 3. Triton X-100 extraction of Cx43/ß-gal and Cx43. Membrane preparations obtained from control (con) or Cx43/ß-gal transfected cells (43ß1, 43ß2) were incubated in Triton X-100 at 4°C for 30 minutes and then centrifuged at 100,000 g for 30 minutes to separate Triton X-100 soluble (sol) and insoluble (ins) fractions. The soluble and insoluble fractions were then resolved by electrophoresis, and detected by immunoblot for Cx43/ß-gal (A) and Cx43 (B). Cx43 samples that had the best resolution of the three Cx43 isoforms are shown. The amount of Triton X-100 soluble Cx43 (C) and Cx43/ß-gal (D) was determined by densitometry. The amount of Cx43 in the Triton X-100 soluble fraction was significantly higher for 43ß2 cells, consistent with decreased incorporation into gap junction plaques. *Statistically significant from control (P<0.05).