Isolation of plasmid DNA from viridans group streptococci is difficult, and preparations are often heavily contaminated with chromosomal DNA. We developed a simple protocol to isolate pure plasmid DNA for use in different molecular techniques, including automated sequencing. The protocol is also applicable for plasmid isolation from Staphylococcus aureus. In addition, the protocol allows isolat...

Present study describes the results of an efficient protocol for the isolation of good quality DNA from human saliva. The protocol includes collection of saliva in sterile specimen tubes, followed by the cell lysis. After formation of cell lysate, proteins wereextracted by phenol chloroform treatment for purification of DNA. The purified DNA was precipitated by adding equal volume of isopropano...

Background: Current prenatal diagnosis requires invasive testing which carries a 1-4% procedure-related-risk of miscarriage; hence, non-invasive techniques are desired. The recent demonstration of cell-free-fetal-DNA enriched from maternal plasma has opened new possibilities for non-invasive-prenatal-diagnosis of not only genetic-disorders such as β-thalassaemia and haemophilia but also chromos...

objective: in this study, the possibility of prenatal diagnosis of down syndrome with real-time pcr method was evaluated. in this context, optimization of a suitable method for purification of high quality dna from amniotic fluid samples was also considered. materials and methods: pregnant women who had the high risk of having babies with down syndrome were selected according to the biochemica...

To isolate a functional macromolecular component from bacterial cells, you must accomplish three things. First, you must efficiently disrupt the bacterial cell wall and cell-membrane system to facilitate extraction of desired components. Second, you must work under conditions that either inhibit or destroy the many degradative enzymes (nucleases, proteases) released during cell disruption. Fina...