Double replica electroblotting for the simultaneous phenotyping of C6 and C7, and its application to the examination of bloodstains.

A new reliable and reproducible technique for the simultaneous determination of C6 and C7 types is presented, which employs double replica electroblotting after isoelectric focusing. It permitted clear discrimination of both C6 and C7 components, and the patterns were nearly comparable to those demonstrated separately. The population data obtained by this new technique fitted the genetic hypothesis. The present double replica electroblotting method was successfully applied to the combined phenotyping of C6 and C7 from bloodstains which were stored at room temperature for up to 4 weeks. The method is quite suitable for medicolegal examination of bloodstains particularly for the saving in the amount of sample.