What is STRs in DNA fingerprinting?

Short tandem repeats (STRs) are short repeated sequences of DNA (2–6 bp) that account for approximately 3% of the human genome (Lander et al., 2001). The number of repeat units is highly variable among individuals, which offers a high power of discrimination when analyzed for identification purposes.

How many STR loci are analyzed for a DNA fingerprint?

13 core STR
In fact, the Federal Bureau of Investigation (FBI) has identified 13 core STR loci that are now routinely used in the identification of individuals in the United States, and Interpol has identified 10 standard loci for the United Kingdom and Europe.

Where are STRs found?

Most STRs are found in the noncoding regions, while only about 8% locate in the coding regions (3). Moreover, their densities vary slightly among chromosomes. In humans, chromosome 19 has the highest density of STRs (4). On average, one STR occurs per 2,000 bp in the human genome (5).

How many STR loci do FBI DNA tests use?

For Forensic STR DNA analysis, the DNA profile consists of one or two alleles at the 20 CODIS Core Loci.

How many STR loci are there?

thirteen loci
The FBI has published its thirteen core loci for the Combined DNA Index System (CODIS) database. STR Fact Sheets are available for all thirteen loci (click on locus name for the STR Fact Sheet).

What are the advantages of STR fingerprinting?

Explanation. In comparison to VNTR fingerprinting, STR fingerprinting is advantageous because it works with shorter DNA strands, makes it easier to separate sequences (because STRs are shorter than VNTRs), is more accurate, and can analyze partially degraded samples.

What are the 13 STR loci?

The 13 STR loci CSF1PO, FGA, TH01, TPOX, vWA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, and D21S11 have been selected as the core loci for use in CODIS (1).

How are STR loci named?

The STR locus is named as, for example, D3S1266, where D represents DNA, 3 means chromosome 3 on which the STR locus locates, S stands for STR, and 1266 is the unique identifier. On the basis of different repeat units, STRs can be classified into different types.