W2L2B: Tools to Study Nucleic Acids

Question 1

Denature

Answer 1

hydrogen bonds between bases in DNA breaking, causing the two strands to come apart; due to high temperatures, extreme pH or ion concentrations

Question 2

Anneal

Answer 2

hydrogen bonds form between two single strands of DNA which are complementary; occurs under lower temperature, and normal pH or ion concentrations

Question 3

DNA Melting Curve

Answer 3

single stranded DNA absorbs more light than double stranded (because bases are hidden in double stranded)

Question 4

DNA Melting Point

Answer 4

the temperature at which 50% of DNA is single stranded (denatured)

Question 5

Probe

Answer 5

small singe stranded piece of DNA, complementary to region of DNA you want to analyze; fluorescent multiple colors detected by microscopy, radioactive detected by exposure of film

Question 6

FISH (Fluorescent in-situ Hybridization)

Answer 6

used to detect specific sequences in the context of the cell or tissue; used to visualize genes in a cell

Question 7

Southern Blot

Answer 7

run a nucleic acid sample of fragmented pieces through an agarose gel, with DNA stained by EtBr, transfer to nitrocellulose membrane, hybridize with nucleic acid probe, use autoradiogram to reveal fragments annealed with probe

Question 8

Gel Electrophoresis

Answer 8

DNA is cleaved into fragments by restriction enzymes and then separated by size

Question 9

Northern Blot

Answer 9

method to measure and analyze specific RNA molecules (similar to Southern blot); probe used typically made of DNA (more stable)