Molecular Diagnostics Chapter 3 Exam 100% Solved

Molecular Diagnostics Chapter 3 Exam 100% Solved Which sample types must be amplified prior to analysis? - answerbuccal cells, saliva, bone, teeth, hair, dried blood, fixed tissue What are two ways to break down cell walls for DNA extraction? - answer1. homogenization through physical grinding 2. treatment of detergent (SDS) with strong base (NaOH) in ethylene- diaminetetraacetic acid (EDTA) Ficoll - answerHighly 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? - answer1. 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? - answerBouin's and B-5 Which fixative is the best for DNA recovery? - answerbuffered formalin Steps of Organic DNA Extraction - answer1. lyse cells in suspension using alkaline (NaOH) and a detergent (SDS) 2. treat lysed debris with acetic acid and salt, centrifuge to pellet 3. add phenol and chloroform to separate solution into two layers an upper aqueous phase which contains the DNA and a lower organic phase which contains the cell debris ie proteins 4. precipitate DNA with ethanol, centrifuge, remove ethanol and reprecipitate with water/buffer, can add RNAs