Infrared Fluorescent Detection of D1S80 Alleles from Blood and Body Fluid Collected on IsoCode™ Devices

Abstract

A genetic locus D1S80 (pMCT 118) containing variable number of tandem repeats (VNTR) has been used extensively in forensic analysis and paternity testing. In the current research, DNA was isolated from blood, saliva and nasal secretions collected on two types of IsoCode™ paper-based devices. The D1S80 locus was amplified using PCR technology, and the alleles were separated by gel electrophoresis and then detected using an infrared (IR) fluorescence automated DNA sequencer. IR-labeled amplification products were generated from human genomic DNA using oligonucleotide primers, which were covalently linked to an infrared fluorescent dye (IRD41) at the 5′ end. This system combines IR fluorescence chemistry and laser technology, thus eliminating the need for post-electrophoretic gel handling for the detection of the alleles. Real-time detection after separation of the alleles is valuable for visualization of the data. The VNTR alleles are displayed as familiar autoradiogram-like images, which can also be analyzed by computer. Since DNA is eluted from the IsoCode devices only with sterile distilled water and without time-consuming methods of extraction, amplification can be performed from numerous samples within a short period of time.