[Sequencing of a large off-ladder allele at Penta E locus].

Objective To identify a rare large off ladder (OL) allele at the Penta E locus. Methods Chelex-100 was used to extract DNAs from the blood samples. The PCR fragments were purified, extracted, and subjected to TA cloning and sequencing. Results An OL allele was identified by the PowerPlex○R 21 at the Penta E locus, which was postulated as allele 26 based on assigned size. The OL allele was verified as a novel fragment containing 26 full AAAGA repeats. Conclusion OL alleles and microvariants should be verified by direct sequencing. Typing of OL alleles has significance for both daily work and forensic genetics. Key words: Forensic genetics; Microvariant allele; Short tandem repeat; Gene sequencing; Penta E allele