
The Complete Guide for Short Tandem Repeats and Its Implementation Importance - benniebio
http://www.creative-bioarray.com/Services/Short-Tandem-Repeat-Analysis.htm
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benniebio
The Importance of STR Analysis It is still common for cell lines to be
misidentified and cross-contamination, although scientists use a variety of
traditional methods to identify cells, there are still dozens of cross-
contamination happened. And even some researchers found that cell lines were
misidentified or cross-contamination while cell identification reports for the
higher score study articles publication, resulting in erroneous conclusions.
All of which will lead to the waste of research funding and time, and
resulting in a large number of invalid or erroneous data that will mislead
other researchers. Based on the statistics data, around 20% of the cell lines
were misidentified and cross-contamination in the labs so that it is a serious
concern for researchers to provide accurate cell line identification and
prevent cell lines from cross-contamination. Currently, several STR loci have
been developed to analyze cross-contamination and cell types at the same time,
that can detect up to 0.1 ng of DNA (about 15 Diploid genomes) with high
sensitivity for the trace pollution.

All the mentioned above is the complete guide for the Short Tandem Repeat and
its importance!

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benniebio
Brief Introduction for Short Tandem Repeats Microsatellite DNA, also known as
short tandem repeats (STR) or simple repeat sequences (SRS or SSR), is widely
found in prokaryotic and eukaryotic genomes, consisting of a unit of two to
thirteen nucleotides repeated hundreds of times in a row on the DNA strand
which is about 5% of the eukaryotic genome, the basic unit (core sequence) is
1-6bp. The most common of these is (CA) n and (TG) n, and the human genome has
about 5 × 104 ~ 1 × 105 (CA) n repeats which take 10% of the genome. Each
microsatellite DNA has the same core sequence structure, the number of
repeating units is about 10 to 60 times, and its length is generally not more
than 300bp, mostly located in the non-coding region of the gene, intron or
untranslated region. which may be present in the Alu sequence or Satellite
sequence, but in the coding sequence and exon also can find the presence of
microsatellite DNA.

The high polymorphism of microsatellite DNA is mainly due to the difference in
the number of tandem numbers. There is a big difference of the distribution
for microsatellite DNA in different races and populations due to the number of
repeat units and repetition, which constituted STR genetic polymorphism. And
the number of repetitions between different individuals at a homologous STR
site is also different so that STR loci analysis can identify individuals that
are similar to fingerprint recognition. It is possible to create a personal
gene file by identifying a specific sequence of genomes at particular loci.
Currently, there are more than 10,000 STR loci are available. STR analysis has
become an important analytical method for individual identification and
paternity testing in the field of forensic science. It can be applied to
judicial case investigation, that is, genetic fingerprint analysis.

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benniebio
STR Detection Method STR analysis is one of the most useful methods in
molecular biology which is used to compare specific loci on DNA from two or
more samples. There are two common methods for STR detection: capillary
electrophoresis (CE) and gel electrophoresis, which can be used to determine
the specific amount of microbes Satellite sequence and draw the STR map.
Typically, each allele is shared by about 5-20% of people. And the advantages
of STR analysis will be reflected in the simultaneous identification of
multiple STR loci. Each individual can be identified accurately by the
resulting STR map. In theory, if there were 16 STR loci being used in
combination, the recognition rate will be 0.999999999998.

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benniebio
The Causes of STR The replication slip caused by mismatches between DNA
strands during the mitotic process is considered to be the most common cause
of the occurrence of STR, and in general, there will be an average of one-
thousandths of microsatellite DNA will undergo replication slippage. The study
showed that the rate of tandem duplication at repeat sequences was higher than
the probability of point mutations occurring elsewhere in the genome. Most of
the replication slides only cause a change in the repeat unit, and the
probability of replication slip is different due to the size of the different
copy units and different species.

