Molecular Diagnostics Nucleic Extraction Methods questions with correct answers

Which sample types must be amplified prior to analysis? - Answer buccal cells, saliva, bone, teeth, hair, dried blood, fixed tissue What are two ways to break down cell walls for DNA extraction? - Answer 1. homogenization through physical grinding 2. treatment of detergent (SDS) with strong base (NaOH) in ethylene-diaminetetraacetic acid (EDTA) Ficoll - Answer Highly branched sugar Solution w/ specific density that allows only RBCs and neutrophils to pass through Mononuclear cells (monocytes and lymphocytes) form a band on top What are two methods for separating nucleated cells? - Answer 1. density-gradient centrifugation of whole blood or bone marrow with ficoll 2. incubation of whole blood or bone marrow in hypotonic water which will lyse RBC's prior to WBC's, and then centrifuged to pellet the WBC's Which fixative is the worst for DNA recover? - Answer Bouin's and B-5 Which fixative is the best for DNA recovery? - Answer buffered formalin Steps of Organic DNA Extraction - Answer 1. lyse cells in suspension