genetic engineering 1 Flashcards
what is genetic engineering?
modification of an organsims genetic composition by artificial means
what processes can be used to visualixe/detect DNA , RNA and protein in a homogenate?
DNA - southern blottin
RNA-northern blotting
protein - western blotting
what processes can be used to visualize DNA in situ?
DNA - chromosome painting
RNA- in situ hybridisation
Protein - immunihistochemistry
giev advantages/diadvantages of homogenate and in situ
homogenate advantage is you can see size and isolate component but large quantity of tissue required
in situ - can see distribution but requires tissue processing
give 3 steps in blotting
size separation in gel (electrophoreses)
transfer onto membrne (blotting)
detect on membrane using labelled probes
what does DNA move in electrophoresis?
moves from negative to positive (DNA - charge)
larger strands move slower as is more resistant in gel
why might protein charge not be negative?
because of side chains
what gel is best for small peices of DNA?
polyacrylamide gel
what is most common gel used?
agarose gel
what factors affect migration of DNA?
gel used, current used, size of DNA, concentration of gel , DNA shape
how does DNA shape effect velocity through gel?
if more compact-move faster
supercoiled moves faster than linear
linear moves faster than circular (plasmid)
name 2 ways of blotting
capillary action, electric field
how is protein on western blot detected?
specific antigen-antibody interaction
