Comparison of human blood serum DSC profiles in aqueous and PBS buffer solutions

The results of studies of physiological fluids by differential scanning calorimetry (DSC) for the purpose of diagnosis and monitoring of diseases are promising. Before the DSC method is accepted in medical diagnostics, it is worth experimenting with various environmental conditions at the research stage. Among other things, it is important to choose an appropriate solvent to dilute the tested biological fluids. In this work, human blood sera DSC profiles in aqueous and PBS (phosphate-buffered saline) solutions have been compared. Visibility of haptoglobin in the DSC profile of human blood serum is much better in water solution. In addition, contributions from albumin and haptoglobin are well separated in contrast to the PBS serum solutions. The peak or shoulder at about 83 °C which represents contributions from the CH3 domain of immunoglobulin IgG1 and/or transferrin is more clearly visible in PBS solution. The results show that the type of solvent is essential when interpreting the serum DSC profile.