Differential extraction

Differential extraction refers to the process by which the DNA from two different types of cells can be extracted without mixing their contents. The most common application of this method is the extraction of DNA from vaginal epithelial cells and sperm cells from sexual assault cases in order to determine the DNA profiles of the victim and the perpetrator. Its success is based on the fact that sperm cells have protein disulfide bonds in their outer membrane which makes them more resilient to extraction than epithelial cells.

After determining that sperm cells are present (typically through staining and light microscopy) in a vaginal/rectal sample, the subject's epithelial cells are lysed by a standard DNA extraction method, like a phenol/chloroform extraction and their DNA extracted through normal means. The epithelial DNA in solution is removed and saved, while the sperm cells are still intact. Differential extraction uses a chemical called dithiothreitol (DTT) to disrupt the sulfur bonds in the coating of the sperm cell in order to extract its DNA. Once the sperm's outer membrane has been breached, it is prone to standard DNA extraction methods. This creates two different DNA fractions from one sample, hopefully that of the victim and that of the perpetrator.

References

External links

• Sperm Isolation - Eliminate epithelial cell DNA from samples containing mixtures of sperm cells and epithelial cells

This forensics-related article is a stub. You can help Wikipedia by expanding it.v · Categories: DNA profiling techniques Forensics stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем написать курсовую Dereham Town F.C. United Nations Security Council Resolution 688 Look at other dictionaries: differential extraction —    A step wise extraction procedure designed to separate intact sperm heads from lysed sperm and other cell types. The separation generally results in an enrichment of sperm DNA in one cell fraction relative to the other cell fraction. The… …   Forensic science glossary Extraction Différentielle — L’extraction différentielle est un procédé de séparation de deux sortes de cellules. L’utilisation la plus courante de cette méthode est la séparation des cellules épithéliales vaginal des cellules du sperme lors d’analyse ADN suite à un viol,… …   Wikipédia en Français Extraction differentielle — Extraction différentielle L’extraction différentielle est un procédé de séparation de deux sortes de cellules. L’utilisation la plus courante de cette méthode est la séparation des cellules épithéliales vaginal des cellules du sperme lors… …   Wikipédia en Français Extraction différentielle — L’extraction différentielle est un procédé de séparation de deux sortes de cellules. L’utilisation la plus courante de cette méthode est la séparation des cellules épithéliales vaginal des cellules du sperme lors d’analyse ADN suite à un viol,… …   Wikipédia en Français Extraction of petroleum — Pumpjack on an oil well in Texas The extraction of petroleum is the process by which usable petroleum is extracted and removed from the earth. Contents 1 …   Wikipedia Shale oil extraction — Shell s experimental in situ shale oil facility, Piceance Basin, Colorado, United States Process type Chemical Industrial sector(s) Chemical industry, oil indus …   Wikipedia Feature extraction — In pattern recognition and in image processing, Feature extraction is a special form of dimensionality reduction.When the input data to an algorithm is too large to be processed and it is suspected to be notoriously redundant (much data, but not… …   Wikipedia test — 1. To prove; to try a substance; to determine the chemical nature of a substance by means of reagents. 2. A method of examination, as to determine the presence or absence of a definite disease or of some substance in any of the fluids, tissues,… …   Medical dictionary DNA profiling — Not to be confused with Full genome sequencing. Forensic science …   Wikipedia fish processing — Introduction       preparation of seafood and freshwater fish for human consumption.       The word fish is commonly used to describe all forms of edible finfish, mollusks (e.g., clams and oysters), and crustaceans (e.g., crabs and lobsters) that …   Universalium 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”