Steps of analyzing DNA Evidence : The Several Basic Steps performed regardless of the type of test being done
1. the isolation of the DNA from an evidence sample containing DNA of unknown origin, and eventually the isolation of DNA from a sample (e,g blood) from a known individual (suspect or victim)
2. The processing of the DNA so that the test results may be obtained
3. The determination of the DNA test results (or types), from specific regions of the DNA
4. The comparison and interpretation of the test results from the unknown and known samples to determine whether the known individual is not the source of DNA or is included as a possible source of the DNA
5. any probative bilogical sample that has been stored dry or frozen, regardless of age, may be considered for DNA analysis
2. The processing of the DNA so that the test results may be obtained
3. The determination of the DNA test results (or types), from specific regions of the DNA
4. The comparison and interpretation of the test results from the unknown and known samples to determine whether the known individual is not the source of DNA or is included as a possible source of the DNA
5. any probative bilogical sample that has been stored dry or frozen, regardless of age, may be considered for DNA analysis
Biology and the DNA'S Genetic role in providing evidence
1. following the collection of biological material from a crime scene of paternity investigation, the DNA is first extracted from its biological source material and then measured to evaluate the quantity of DNA recovered
2. after isolating the DNA from its cells, specific regions are copied with a technique known as the polymerase chain reaction or PCR
3. PCR produces millions of copies for each DNA segment of interest and thus permits very minute amounts of DNA to be examined
4. Multiple STR* regions can be examined simultaneously to increase the informativeness of the DNA Test
2. after isolating the DNA from its cells, specific regions are copied with a technique known as the polymerase chain reaction or PCR
3. PCR produces millions of copies for each DNA segment of interest and thus permits very minute amounts of DNA to be examined
4. Multiple STR* regions can be examined simultaneously to increase the informativeness of the DNA Test
Genetic Role
`1. The resulting DNA profile for a sample, which is a combination of the indivudal STR genotypes, is compared to other samples. in case of a forensic investigation, these other samples would include known reference samples such as the victims or suspects that are compared to the crime scene evidence
*STR (Short Tandem Repeat): Short tandem repeats (STRs), which are sometimes referred to as micro- satellites or simple sequence repeats (SSRs), are accordion-like stretches of DNA containing core repeat units of between two and seven nucleotides in length that are repeated from approximately a half dozen to several dozen times.
*STR (Short Tandem Repeat): Short tandem repeats (STRs), which are sometimes referred to as micro- satellites or simple sequence repeats (SSRs), are accordion-like stretches of DNA containing core repeat units of between two and seven nucleotides in length that are repeated from approximately a half dozen to several dozen times.