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™ 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.