Electrophoretic patterns of serum albumins collected from different blood vessels

Further studies on the electrophoretic pattern of albumin in diabetic sera

Human sera from normal subjects and diabetic patients were electrophoresed in an urea-containing gel; polyacrylamide gel and cellulose acetate membrane. In polyacrylamide gel, normal serum exhibited the fast migrating Band 2 and the slower migrating albumin Bands 4 and 5 after overnight fasting and also after glucose administration. In diabetic serum Bands 4 and 5 did not appear before or after glucose administration in low mercaptoethanol gel which abnormality resembled the pattern in C57BL/KsJ-db/db mice. In high mercaptoethanol gel, about half of the diabetic sera exhibit a delay in appearance of Bands 4 and 5, i.e., Bands 4 and 5 were not observed 30--60 min after glucose administration, which seems to resemble the pattern in C57BL/6J-ob/ob mice. Conditions of electrophoresis in urea-submerged cellulose acetate membrane (species of buffer systems, pH, ion concentration, mercaptoethanol, ethylene-diaminetetraacetic acid, Ca2+ ion, urea concentration, etc.) were observed in relation to albumin sub-separation. At pH 8.6 with barbital buffer, albumin separated into two bands, and at pH 10.6 with glycine buffer, albumin separated into four bands. Almost all diabetic sera (ca. 80%) exhibited different electrophoretic patterns from that of normal serum.