Derivative analysis in differential scanning calorimetry of model biomembranes

Abstract

The thermogram obtained from a differential scanning calorimeter can be digitised and subjected to numerical analysis to provide multiple derivatives of the parent curve. This treatment is shown to enhance both the accuracy in determining onset temperatures and the ability to detect multiple components in the thermograms of lipid dispersions. When analysed by this technique, mixtures of 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) and 1,2-distearoyl- sn-glycero-3-phosphocholine (DSPC) are found to exhibit, over a wide range of compositions, a complex melting behaviour which is highly dependent on the thermal history of the sample.