DNA barcoding is a molecular biology method that identifies species based on the sequence of a small fragment of DNA. DNA barcodes can be generated for known species and act as a future reference, or they can used to identify the species of an unknown sample. There is no gene that acts as a universal barcode, but the mitochondrial gene, Cytochrome Oxidase I, and the chloroplast gene, RBCL, are two of the most commonly used. To date, there are over 130,000 species with vouchered DNA barcodes and over 2 million barcode sequences.
Unit 1: Sampling Local Biodiversity
Collecting local samples of interest is the first step in generating a DNA barcode. Sample collection can be done just about anywhere but what matters most is documenting information about how and where the samples were collected. This curriculum introduces students to sampling invertebrates at a local park along with the materials and methods used for sampling. For this unit we have included data sheets, information on calculating biodiversity using the Simpson's Diversity Index, and an outline and rubric for writing up a final scientific paper.
In order to work with DNA students must be familiar with basic molecular biology technology as well as master specific skills. This unit introduces students to DNA extraction, Polymerase Chain Reaction (PCR) and gel electrophoresis as well as how to work with small volumes using micropipettes.
In this unit, students are introduced to what DNA barcoding is, why it works, and how it works. In this unit we provide information about the science and theory of DNA barcoding, scientific papers using DNA barcoding methods, as well as protocols that have been modified for use in high schools.
Analysis of DNA barcodes uses bioinformatics programs to compare the sequence data. This unit introduces users to two systems that are uniquely designed for DNA barcoding, Cold Spring Harbor Laboratory's DNA Subway and The Barcode of Life Data Systems - Student Data Portal.
Unit 5: Generating DNA Barcoding Research Questions
Our final unit is designed for students to generate their own questions that incorporate the science and techniques they have learned in the previous four units. We also provide examples of the kinds of questions that students have asked using DNA barcoding and how these questions can address local issues from mislabeling of fish to better manage fisheries to identifying populations of bed bugs in New York City.