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Calf thymus DNA was reacted in vitro with phenyl glycidyl ether (PGE) and was hydrolysed enzymatically, to the 5'-monophosphate nucleotides using deoxyribonuclease I (DNA-ase I) and nuclease P1. The adducts were concentrated using solid phase extraction (SPE), on a polystyrene divinylbenzene copolymer in order to remove the unmodified nucleotides. The adducts could be identified using capillary zone electrophoresis-electrospray tandem mass spectrometry (CZE ES-MS/MS), using sample stacking. In addition to the base alkylated 2'-deoxynucleotides present in the DNA-hydrolysate, also phosphate alkylated 2'-deoxynucleotide adducts were identified for TMP and dAMP. An additional adduct, dUMP alkylated on the uridine moiety was found originating from the hydrolytic deamination of dCMP alkylated on N3 of the cytosine moiety. Enzymatic hydrolysis using nuclease P1 was incomplete as shown by the presence of dinucleotides alkylated on the base moiety. They were successfully hydrolysed to the corresponding 2'-deoxynucleotides by snake venom phosphodiesterase (SVP). Data are shown indicating that alkylations on the pyrimidine bases were more resistant to enzymatic hydrolysis with nuclease P1 than the purine alkylated products.

Allele frequencies of four short tandem repeat loci (HumCD4, HumTH01, HumD21S11 and HumSE33) were investigated in a sample of 395 unrelated Belgian individuals using multiplex polymerase chain reaction and capillary electrophoresis. Automated laser fluorescence was used to detect four fluorescent dyes, enabling the use of an internal standard within each lane. With this method rapid typing with high resolution was obtained and the different alleles were grouped on a statistical base. All loci meet Hardy-Weinberg expectations. The allelic frequency data, together with the constructed allelic ladder, can be used in paternity testing and personal identification in the medical and forensic sciences.

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