A panel of Y-specific STR loci, including DYS19, DYS389, DYS390, DYS391, DYS392, and DYS393 was analyzed using horizontal nondenaturing polyacrylamide gel electrophoresis with a discontinuous buffer system (horizontal disk-PAGE). In order to obtain correct results for the larger DYS389 and DYS392 alleles, it was necessary to design new primers that bind closer to the repeat region and lead to a significant reduction of the amplified fragment size. Using the modified primer sets the horizontal disk-PAGE results were consistent with a nondenaturing approach using fluorescent primers and a 377 automated sequencer. The modified procedure also amplifies the second repeat stretch at the duplicated DYS389 locus as a single fragment, which results in an immediate allele identification. The results indicate that horizontal disk-PAGE with silverstaining is a simple approach to type the recommended Y-specific STR markers.

Phenotypes of inter-alpha-trypsin-inhibitor (ITI) have been determined by isoelectric foCUSing on polyacryl-amide gels followed by immunofixation. The phenotype fre-quencies of ITI in the Han population in Chengdu. P. R. China have been investigated using this method. In addition, family studies have been conducted in 21 families. The re-suits show that ITI iS polymorphic in the Han population in Chengdu. China. The allele frequencies are as follows: ITI*1=0.5763. ITl*2=0.4107. ITl*3=0.0130. ITI is thus a new and promising genetic marker that can be used in the field of forensic haematogenetics.

Single nucleotide polymorphisms (SNPs) are new generation markers. An open question in research on SNPs is how to find novel SNPs in a nature population. To this end, we developed an approach of high-throughput genotyping by applying the temperature-modulated heteroduplex analysis (TMHA) based upon ion-pair reversed-phase high-performance liquid chromatography. This approach allowed a very efficient resolution of identically sized PCR products with a single nucleotide change. This approach was also known as denaturing high-performance liquid chromatography (DHPLC). However, the terms of both TMHA and DHPLC should be considered carefully. The term of DHPLC may lead to confusion in annealing and denaturing. Since TMHA can be carried out using gel electrophoresis and HPLC, there is a need to distinguish HPLC from gel electrophoresis. Therefore, we suggest a new term for this technology, which is temperaturemodulated high-performance liquid chromatography (TmHPLC). This term not only provides a clear definition for this new method, but also includes both TMHA and HPLC. More importantly, TmHPLC implies that the temperature in HPLC is modulated according to Tm of the DNA fragments. Our results show that TmHPLC is a sensitive, accurate and cost effective approach to screening sequence variation in human genome.