Figure 5: Effects of divalent metal ions on the EDTA-mediated inhibition of SRBC hemolysis by crocodile serum. Incubation of 1% SRBCs (v/v) with O. tetraspis or M. cataphractus serum in the presence of 1 mM EDTA inhibited hemolysis. However, addition of 5 mM Ca2+ or Mg2+ but not Ba2+, Cu2+, or Fe2+, reversed the EDTA-mediated inhibition. The results are expressed as % of maximum hemolysis, relative to a positive control, and represent the results of four independent determinations.