[Study on application of Tf subtyping in forensic medicine].

Tf is an important genetic marker for both parentage testing and personal identification in forensic medicine. It is valuable in anthropology, genetics and clinical medicine. We examined the Tf subtypes in the human serum and dried bloodstain using the ULPAGIF method. Tf subtyping was performed in four disputed parentage cases. One of the alleged fathers was excluded. Tf subtypes were successfully demonstrated from dried bloodstains kept at 4 degrees C for up to four weeks. In bloodstains kept at room temperature and 37 degrees C, the 100% of Tf subtyping was no longer possible after two weeks (or one day). It was suggested that the bloodstains should be examined no longer than seven weeks if the bloodstains were kept at room temperature; or otherwise they should be stored below 4 degrees C as soon as they are collected in forensic practice.