Immunoprecipitation is a technique in which an antigen is isolated by binding to a specific antibody attached to a sedimentable matrix. It is also used to analyze protein fractions separated by other techniques such as gel filtration or density gradient sedimentation. The source of antigen for immunoprecipitation can be unlabeled cells or tissues, metabolically or intrinsically labeled cells, or in vitro-translated proteins. This unit describes a wide range of immunoprecipitation techniques, using either suspension or adherent cells lysed by various means.Usually, plasmas transfected cells or natural cells are ideal sample for immunoprecipitation.
A HeLa cell /ˈhiːlɑː/, also Hela or hela cell, is a cell type in an immortal cell line used in scientific research. It is the oldest and most commonly used human cell line. The line was derived from cervical cancer cells taken on February 8, 1951, from Henrietta Lacks, a patient who eventually died of cervical cancer on October 4, 1951. The cell line was found to be remarkably durable and prolific — which has led to contamination of many other cell lines used in research.
The cell line from Lacks's tumor were taken without her knowledge or consent by researcher George Gey, who found that they could be kept alive. Before this, cells cultured from other cells would only survive for a few days. Scientists take more time to keep the cells alive than performing actual research on the cells, but some cells from Lacks's tumor sample behaved differently from others. George Gey isolate one specific cell, multiply it, and start a cell line. Gey named the cells HeLa, after the initial letters of Henrietta Lacks' name. As the first human cells grown in a lab that were "immortal" (they do not die after a few cell divisions), they could be used for many experiments. It represented an enormous progress to medical and biological research.
The stable growth of HeLa cells enabled a researcher at the University of Minnesota hospital to successfully grow polio virus, enabling the development of polio vaccine. By 1954 Jonas Salk developed a vaccine for polio using these cells. To test Salk's new vaccine, the cells were quickly put into mass production in the first-ever cell production factory.
In 1955 HeLa cells were the first human cells successfully cloned. Demand for the HeLa cells quickly grew. Since they were put into mass production, Lacks's cells have been used by scientists over the world for "research into cancer, AIDS, the effects of radiation and toxic substances, gene mapping, and countless other scientific pursuits". HeLa cells have been used to test human sensitivity to tape, glue, cosmetics, and many other products. Scientists have cultured over 20 tons of hela cells, and there are almost 11,000 patents involving HeLa cells.