The effect of sodium chloride and calcium chloride on the main phase transition of dimyristoylphosphatidylcholine

Differential scanning calorimetry is employed at a scan rate of 2 K h(-1) to study the effects of sodium chloride and calcium chloride on the main phase transition of dilute aqueous suspensions of dimyristoylphosphatidylcholine. The primary effect of sodium chloride over the concentration range studied, 0-5 molar, is to raise the transition temperature. In the case of calcium chloride, studied over the range 0-2 molar, the increase in the transition temperature is much larger, and the transitions become unsymmetrical and much broadened at concentrations above 0.75 M. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.