Transfer of hemolysis-inducing and glycophorin-cleaving activity.

E were treated with increasing concentrations of P1 (•), P2 (○), orL. intermedia venom (*), washed, and incubated with the same volume and number of calcein-AM loaded E or buffer. After 30 minutes of incubation at 37°C, cells were analyzed for autologous C lysis (A, B) or for the expression of GPC (C). (A) Total hemoglobin release induced by NHS determined spectrophotometrically at 541 nm. (B) Release of entrapped calcein determined fluorometrically. [C] E samples incubated with buffer or with P2 (2.5 and 5.0 μg/mL) were incubated with the same volume of untreated E (□) or with buffer (▪) for 30 minutes at 37 °C and analyzed by flow cytometry for expression of GPC using the monoclonal antibody Bric4. Results are expressed as the percentage of fluorescence of untreated E.