Quality Assessment in Silica-extraction of Extraction DNA from Paraffin-embedded Tissue Using Identifiler Kit
|School||Nanjing Medical University|
|Course||Pathology and Pathophysiology|
|Keywords||paraffin-embedded tissue DNA silica-extraction phenol-chloroform-extractio|
Research has shown that human DNA is the main genetic material, but thegenome is not as stable as people imagine. Gene rearrangement、 amplification、deletion、 mutation and DNA methylation changes the regulation and expression ofgenes, as well as the disease process. Therefore, since the James Dewey Watson andFrancis Crick found the DNA double helix structure, accompanied by molecularbiology technology more and more widely used in the field of human diseases, theresearch of human physiological and pathological conditions mainly is focused onDNA. Its physicochemical properties and function are the hotspot. Many geneticdiseases, cancer and DNA are closed related. For further study of DNA changesinduced by the corresponding pathological findings, many researchers select cell,animal model to research the related diseases. In recent years, paraffin-embeddedtissue block has gradually become a new research material. Goelz (1985) and Dubeau(1986) successfully got high quality DNA from the wax block and fully was able tomeet the molecular biology of cancer research. It is end of that DNA studyingdependent on fresh or frozen tissue. It is great value of diagnosis, differentialdiagnosis and prognosis assessment. Paraffin-embedded tissue blocks become studymaterial for DNA has many advantages. Paraffin-embedded is surgical specimens thatis directly from the individuals and most directly reflects the underlying diseasechanges; it is the good control that get the tumor and normal tissues at the same timein the study of neoplasia;paraffin section is not only used to observe the morphologyof the normal tissue, but also is the main method of pathology and forensic medicine and other disciplines for the research to observation and judgment of themorphological changes of the tissue. After a series processing of tissue block，samplecan be saved in paraffin permanently, you can get a large number of samples,become very good retrospective study materials. Literature reports wax blockembedded tissue also has limitation. Produced process by alcohol and xylene andother organic solution, so it is easy to cause tissue antigen losing. Studies have shownthat, a fixing types directly affects the extraction quality of DNA; with the fixed time,DNA with protein cross-linking produces more, to obtain the DNA will become less;the composition, concentration, pH of fixing and temperature will also have certaininfluent the DNA extraction. As many factors, getting high quality and highmolecular weight DNA also have some problems need to be solved. Reported in theliterature, silica extraction method is often used in highly corrupt and trace samples,but for paraffin-embedded tissue extraction reported in the literature is not much. Theexperimental uses the advantage of silica firmly bonding the DNA. The results bystatistical calculation showed the silica-extraction was better than organic method,and also in the molecular weight of DNA. The study discusses various methods ofDNA extraction, hoping for future research to provide some basic data.