U.S. flag

An official website of the United States government, Department of Justice.

Non-STR DNA Markers: SNPs, Y-STRs, LCN and mtDNA

Linear Array Analysis

Home  |  Glossary  |  Resources  |  Help  |  Contact Us  |  Course Map

The Linear Array mtDNA HVI/HVII Region-Specific Typing Kit (Roche Applied Science) is a sequence-specific oligonucleotide hybridization technique.28 This technique is used as a screening assay and eliminates the need to perform more costly direct sequencing of all samples.

Mitochondrial DNA Reference Guide
National Institute of Justice (NIJ) (see reuse policy).



A detective submits a single pubic hair for mtDNA analysis, the victim reference standard, and standards for ten suspects. With the linear array assay, the analyst may be able to exclude the victim and eight suspects as the donor of the pubic hair. This would leave three samples needing direct sequencing: the pubic hair sample and the samples from the two suspects not excluded.
Mitochondrial DNA Linear Array Analysis Graph
National Institute of Justice (NIJ) (see reuse policy).

The linear array assay has sequence-specific oligonucleotide (SSO) probes immobilized on a membrane very similar in design to the AmpliType PM + DQA1 Typing Kit.29 Biotinylated PCR (Polymerase Chain Reaction) products hybridize to the SSO probes with the exact sequence complement.  Common polymorphic sites are interrogated.28 All biotinylated PCR products hybridized to the SSO probes are detected with streptavidine-horseradish peroxidase conjugate. A chromogenic substrate produces a blue precipitate on the membrane. It is this pattern of "thin blue lines" that detects sequence variants to the rCRS. All samples not excluded with this typing kit can be analyzed with direct sequencing methods to evaluate the full hypervariable regions, using the original amplicons. Data is reviewed to obtain additional sequence information to confirm the original match or determine it to be a non-match.

Back Forward