Multiplex STR Kit
Definition
Single-tube PCR amplifying 15+ STR loci plus amelogenin in one reaction. AmpFISTR Identifiler Plus and PowerPlex are the workhorses in Indian DNA labs.
- Loci amplified
- 15 or more STR loci plus amelogenin
- Method
- Single-tube PCR reaction
- Common kits
- AmpFlSTR Identifiler Plus, PowerPlex
- Use setting
- Routine DNA profiling in Indian forensic labs
Common questions
Why is amplifying all loci in one tube preferable to separate reactions?+
A single multiplex reaction conserves limited or degraded sample DNA and reduces the chance of cross-contamination or handling error compared to running each locus separately, while also cutting analysis time and cost.
What happens when a sample is too degraded for a full multiplex kit to work?+
Some loci may drop out or show only partial amplification, producing a partial profile; labs then either accept the reduced number of loci for a lower-power comparison or switch to mini-STR kits designed for shorter, more degradation-resistant amplicons.
Related terms
- Autosomal vs Mitochondrial DNA
- Autosomal DNA is nuclear, biparentally inherited, present as two copies per cell. Mitochondrial DNA is cytoplasmic, maternally inherited, present in hundreds to...
- Capillary Electrophoresis
- Size separation of fluorescently labelled PCR products through a polymer-filled capillary on an instrument like the ABI 3500. Output is an electropherogram.
- Chromosome
- A discrete, condensed structure consisting of a single long DNA molecule complexed with histone proteins. Humans normally carry 46 chromosomes in 23...
- CODIS
- The FBI's Combined DNA Index System, the US national STR-based forensic DNA database. Contains profiles from convicted offenders, arrestees, and unidentified crime-scene...
- Nucleotide
- The monomer unit of nucleic acids. Each nucleotide consists of a five-carbon sugar (deoxyribose in DNA, ribose in RNA), a phosphate group,...
- PCR
- Polymerase Chain Reaction. Kary Mullis 1983. Exponential amplification of a target sequence using a thermostable Taq polymerase, two primers and thermal cycling.
- RFLP
- Restriction Fragment Length Polymorphism. The first-generation DNA typing method using restriction enzymes and Southern blotting. Required nanograms of intact DNA.
- SNP (Single Nucleotide Polymorphism)
- A position in the genome where the nucleotide base differs between individuals. Genome-wide SNP panels are more powerful than STR panels for...
- STR (Short Tandem Repeat)
- A genomic locus where a 2, 7 base-pair unit is repeated in tandem a variable number of times between individuals. The variation...
- VNTR
- Variable Number Tandem Repeats. Longer repeat units (10 to 100 bp) than STRs. The original Alec Jeffreys 1984 fingerprinting markers, now superseded...
- Watson-Crick Base Pairing
- Adenine pairs with thymine via two hydrogen bonds; guanine pairs with cytosine via three. The pairing rule that makes the double helix...