Isotope labeled internal standards (ILIS) as a basis for quality control in clinical studies using plasma samples
For clinical proteomic studies the availability of high quality biofluid samples such as human blood plasma are extremely important. In this study we have investigated the stability of human plasma samples by spiking stable isotope-labeled peptides into the plasma and monitoring their degradation under different storage conditions. FPA-1, C4A and C3f were synthesized with isotopically labeled amin