Transferrin subtyping of bloodstains and semen using isoelectric focusing and immunoblotting

Transferrin (TF) subtyping was carried out on bloodstains that had been made on cotton sheeting and stored under a variety of conditions ranging from −20°C to +37°C. The time limit of detection was longer than 54 weeks after dry storage under each condition. Moreover the correlation between isoprotein types of the TF in blood and semen samples from the same individual was determined in 103 men. All three TF common types and two rare types in all semen samples correlated with the type found in the corresponding blood sample. A combination of isoelectric focusing separation and immuno-enzyme-linked detection may prove to be very useful for forensic TF subtyping.