DNA profiling is the process of determining an individual's DNA characteristics. DNA analysis intended to identify a species, rather than an individual, is called DNA barcoding.
Intracytoplasmic sperm injection is an in vitro fertilization (IVF) procedure in which a single sperm cell is injected directly into the cytoplasm of an egg. This technique is used in order to prepare the gametes for the obtention of embryos that may be transferred to a maternal uterus. With this method, the acrosome reaction is skipped.
Lysis is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a lysate. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles.
A lysis buffer is a buffer solution used for the purpose of breaking open cells for use in molecular biology experiments that analyze the labile macromolecules of the cells. Most lysis buffers contain buffering salts and ionic salts to regulate the pH and osmolarity of the lysate. Sometimes detergents are added to break up membrane structures. For lysis buffers targeted at protein extraction, protease inhibitors are often included, and in difficult cases may be almost required. Lysis buffers can be used on both animal and plant tissue cells.
The first isolation of deoxyribonucleic acid (DNA) was done in 1869 by Friedrich Miescher. Currently it is a routine procedure in molecular biology or forensic analyses. For the chemical method, there are many different kits used for extraction, and selecting the correct one will save time on kit optimization and extraction procedures. PCR sensitivity detection is considered to show the variation between the commercial kits.
Capillary electrophoresis (CE) is a family of electrokinetic separation methods performed in submillimeter diameter capillaries and in micro- and nanofluidic channels. Very often, CE refers to capillary zone electrophoresis (CZE), but other electrophoretic techniques including capillary gel electrophoresis (CGE), capillary isoelectric focusing (CIEF), capillary isotachophoresis and micellar electrokinetic chromatography (MEKC) belong also to this class of methods. In CE methods, analytes migrate through electrolyte solutions under the influence of an electric field. Analytes can be separated according to ionic mobility and/or partitioning into an alternate phase via non-covalent interactions. Additionally, analytes may be concentrated or "focused" by means of gradients in conductivity and pH.
A rape kit is a package of items used by medical personnel for gathering and preserving physical evidence following an allegation of sexual assault. The evidence collected from the victim can aid the criminal rape investigation and the prosecution of a suspected assailant. DNA evidence can have tremendous utility for sexual assault investigations and prosecution by identifying offenders, revealing serial offenders through DNA matches across cases, and exonerating those who have been wrongly accused.
A protein microarray is a high-throughput method used to track the interactions and activities of proteins, and to determine their function, and determining function on a large scale. Its main advantage lies in the fact that large numbers of proteins can be tracked in parallel. The chip consists of a support surface such as a glass slide, nitrocellulose membrane, bead, or microtitre plate, to which an array of capture proteins is bound. Probe molecules, typically labeled with a fluorescent dye, are added to the array. Any reaction between the probe and the immobilised protein emits a fluorescent signal that is read by a laser scanner. Protein microarrays are rapid, automated, economical, and highly sensitive, consuming small quantities of samples and reagents. The concept and methodology of protein microarrays was first introduced and illustrated in antibody microarrays in 1983 in a scientific publication and a series of patents. The high-throughput technology behind the protein microarray was relatively easy to develop since it is based on the technology developed for DNA microarrays, which have become the most widely used microarrays.
Immunoprecipitation (IP) is the technique of precipitating a protein antigen out of solution using an antibody that specifically binds to that particular protein. This process can be used to isolate and concentrate a particular protein from a sample containing many thousands of different proteins. Immunoprecipitation requires that the antibody be coupled to a solid substrate at some point in the procedure.
DNA fragmentation is the separation or breaking of DNA strands into pieces. It can be done intentionally by laboratory personnel or by cells, or can occur spontaneously. Spontaneous or accidental DNA fragmentation is fragmentation that gradually accumulates in a cell. It can be measured by e.g. the Comet assay or by the TUNEL assay.
DNA separation by silica adsorption is a method of DNA separation that is based on DNA molecules binding to silica surfaces in the presence of certain salts and under certain pH conditions, usually conducted on a microchip coated in silica channels.
A semen analysis, also called seminogram, or spermiogram evaluates certain characteristics of a male's semen and the sperm contained therein. It is done to help evaluate male fertility, whether for those seeking pregnancy or verifying the success of vasectomy. Depending on the measurement method, just a few characteristics may be evaluated or many characteristics may be evaluated. Collection techniques and precise measurement method may influence results.
PCR inhibitors are any factor which prevent the amplification of nucleic acids through the polymerase chain reaction (PCR). PCR inhibition is the most common cause of amplification failure when sufficient copies of DNA are present. PCR inhibitors usually affect PCR through interaction with DNA or interference with the DNA polymerase. Inhibitors can escape removal during the DNA purification procedure by binding directly to single or double-stranded DNA. Alternatively, by reducing the availability of cofactors (such as Mg2+) or otherwise interfering with their interaction with the DNA polymerase, PCR is inhibited.
RNA extraction is the purification of RNA from biological samples. This procedure is complicated by the ubiquitous presence of ribonuclease enzymes in cells and tissues, which can rapidly degrade RNA. Several methods are used in molecular biology to isolate RNA from samples, the most common of these is guanidinium thiocyanate-phenol-chloroform extraction. The filter paper based lysis and elution method features high throughput capacity.
Spin column-based nucleic acid purification is a solid phase extraction method to quickly purify nucleic acids. This method relies on the fact that nucleic acid will bind to the solid phase of silica under certain conditions.
Sperm sorting is a means of choosing what type of sperm cell is to fertilize the egg cell. Several conventional techniques of centrifugation or swim-up. Newly applied methods such as flow cytometry expand the possibilities of sperm sorting and new techniques of sperm sorting are being developed.
The Debbie Smith Act of 2004 provides United States federal government grants to eligible states and units of local government to conduct DNA analyses of backlogged DNA samples collected from victims of crimes and criminal offenders. The Act expands the Combined DNA Index System (CODIS) and provides legal assistance to survivors of dating violence. Named after sexual assault survivor Debbie Smith, the Act was passed by the 108th Congress as part of larger legislation, the Justice for All Act of 2004, and signed into law by President George W. Bush on October 30, 2004. The Act amended the DNA Analysis Backlog Elimination Act of 2000, the DNA Identification Act of 1994, the Violence Against Women Act of 2000, and the Uniform Code of Military Justice. The Act was reauthorized in 2008, extending the availability of DNA backlog reduction program grants, DNA evidence training and education program grants, and sexual assault forensic exam program grants through fiscal year 2014.
Rape investigation is the procedure to gather facts about a suspected rape, including forensic identification of a perpetrator, type of rape and other details.
Forensic serology is the detection, identification, classification, and study of various bodily fluids such as blood, semen, saliva, urine, breast milk, vomit, fecal matter and perspiration, and their relationship to a crime scene. A forensic serologist may also be involved in DNA analysis and bloodstain pattern analysis. Serology testing begins with presumptive tests which gives the analyst an indication that a specific bodily fluid may be present, but cannot completely confirm its presence. Following the presumptive tests, are the confirmatory tests that confirms what the unknown substance actually is.
DNA profiling is the determination of a DNA profile for legal and investigative purposes. DNA analysis methods have changed numerous times over the years as technology improves and allows for more information to be determined with less starting material. Modern DNA analysis is based on the statistical calculation of the rarity of the produced profile within a population.
