Figure 2

Example of 4–12% Comassie gel resolution of plasma (P), serum (S), dry blood spots (DBS) eluted at PH 4,5, -7,4, -8,6 and 9, dry plasma spot (DPS) and products of elution from protein saver cards spotted with serum (dry serum spot – DSS) obtained from the same individual’ blood sample. Plasma and serum were diluted 1:100 at room temperature (RT) while DBS were diluted 1:60 after 1 h at 37 °C. The same protein concentration was loaded in each lane for all samples (100 micrograms/lane). Gel bands from P, S and from DPS and DSS appear equivalent. Arrows indicate DBS bands which are different from those obtained from P, S, DPS and DSS, particularly at low molecular weight (red cell lysis products). The bottom large and intense bands in the DBS lanes are likely to be products of haemolysis. The most prominent band just above 71 kDa is albumin. The high concentration of albumin is likely to affect electrophoretic migration, skewing the correspondent band position (with respect to the protein marker, M) slightly above the expected molecular weight (66 kDa). M: protein marker.