DNA Profiling of the D1S80 Locus: A Forensic Analysis for the Undergraduate Biochemistry Laboratory

Abstract

We describe a laboratory exercise in DNA profiling that can be used in an undergraduate biochemistry teaching laboratory to demonstrate four fundamental procedures: isolation of genomic DNA from human (cheek) cells, use of the polymerase chain reaction (PCR) to amplify DNA, separation of amplified DNAs on agarose and polyacrylamide gels, and quantitative analysis of data (while comparing two different gel separation techniques). The target of PCR amplification is the 369–801 base pair D1S80 locus of the human genome, a variable number of tandem repeats (VNTR) locus containing a 16 base pair repeat unit. Students amplify DNA from their entire class, determine the size and genotype of all of the students' D1S80 loci by two gel separation techniques, compare the samples to an "evidence" sample to solve a fictitious crime, and critically evaluate the methodology.

Using The Poisoner’s Handbook in Conjunction with Teaching a First-Term General/Organic/Biochemistry Course

“…Indeed, shows such as CSI , Bones , and Forensic Files have been among some the most popular programs on the air for more than a decade. , The effect that the increased number of crime and forensic television shows has had on science education has been discussed previously . Using forensic science applications to engage students of all ages has a long and well-documented history in this Journal. − Given the large percentage of enrolled students interested in health sciences, and given the public interest in forensic/crime television programs, we believed that reading The Poisoner’s Handbook would serve to pique student interest in the relationship between chemistry and forensic science. We hoped it would also serve as an engaging way for students to learn more about the simple toxins commonly implicated in both accidental and homicidal poisonings in the early 20th century.…”

Curriculum and course materials for a forensic DNA biology course

“…For example, in the Journal of Chemical Education, papers detail DNA typing of the human D1S80 locus implemented as an undergraduate biochemistry laboratory experiment , using mitochondrial DNA to probe a hypervariable region from simulated forensic samples in the biochemistry laboratory , forensic analysis of canine DNA samples from dog hair and saliva in the biochemistry laboratory , probing for a DNA segment present in genetically modified foods , genotype the normal variation in human color vision , evaluate a metabolic polymorphism , designing polymerase chain reaction (PCR) primer multiplexes in the forensic laboratory , amplification and quantitation of human DNA using TPOX locus primers using real‐time PCR in the forensic, biochemistry, or molecular biology laboratory , and introducing microfluidic gel electrophoresis in the undergraduate laboratory applied to food analysis . Other related papers include an article on DNA profiling from convicted offenders for the Combined DNA Index System (CODIS) and an NSF‐funded collaboration between Chemistry and Biology Departments to introduce spectroscopy, electrophoresis, and molecular biology in five different courses .…”

The ethical implications of genetic testing in the classroom

“…Protocols (see Table I) generally begin by acquiring a DNA sample with a buccal swab [3][4][5][6] or saline rinse [7][8][9][10]; saliva [11,12]; blood [13,14]; or ''evidence'' such as teeth, hair or cigarette butts [15]. DNA is extracted most commonly using commercial kits.…”

“…In addition, gene expression can be analyzed using DNA methylation assays [7]. These techniques have been used to analyze a variety of genes, including diurnal preferences [7], lactase persistence [8], blood type [11,13], personal identity [4,6,10,12,15], color vision [5], spirituality tendencies [9], and cancer susceptibility [3,14].…”