Genetic Engineering Flashcards
Name some types of proteins
Structural proteins, enzymes, signalling proteins
What is the function of southern blotting
Detect/visualise DNA in homogenate
Describe homogenate solutions
cellular/organ structure destroyed
Describe in situ structure
cellular/organ structure intact
How is DNA detected/visualised in situ
chromosomal painting/spreads
How is RNA detected in homogenate
Northern blotting
What does western blotting detect
proteins in homogenate
What does imunno-histochemistry detect
proteins in situ
How is RNA detected in situ
in situ hybridisation
What is a disadvantage of using homogenate
requires larger quantity of tissue
What is a disadvantage of in situ methods
require tissue processing
What is useful about in situ techniques
determine sub-cellular location
What are the techniques of blotting
repeated freeze/thaw, mechanical devices, detergents
What is the first step of the blotting technique
DNA is in a gel and separated by size
What is the second step of the blotting technique
transfer out of gel - blotted by electric field or capillary action
What is the third step of the blotting technique
detection with labelled probe
what are the factors affecting DNA migration
DNA size, DNA shape, Gel type, Gel concentration
What type of gel is best for larger fragments of DNA
Agarose
What are the main two types of gel
agarose or polyacrylamide
What does a western blot rely on
principle of specific antigen-antibody interaction
What does the western blot identify
presence of protein, size and relative abundance
What does stability of hybridisation of DNA or RNA rely on?
degree of match between target and probe
What does in situ hybridisation of RNA rely on
principle of hybridisation of complementary probe to target RNA
What can in situ detection of RNA locate
RNA sequences within a tissue
What can in situ detection of RNA detect
mRNA expression
Describe correlation between signal intensity and expression in in situ detection of RNA
As signal intensity increases, level of expression increases
What are the purposes of DNA sequencing
predict function of DNA sequence, identify differences, confirm sequence of engineered DNA
How are nucleotides linked
phosphodiester bond between 5’prime phosphate to 3’prime hydroxyl
What are nucleotide terminators tagged with
fluorescent label
What size fragments run fastest
small
What are the advantages of DNA sequencing
deep sequencing, whole genome in one day, RNA sequencing
What are the purposes of restriction enzymes in DNA sequencing
enable analysis of DNA, enable DNA engineering
What does ligase catalyse
formation of phosphodiester bond
What are the characteristics of restriction enzymes that are useful for DNA engineering
cut at specific sequence, produce compatible cohesive ends
What does PCR require
small amount of DNA, known starting sequence of DNA, DNA polymerase, dNTPs
Where are DNA primers derived from in PCR
start and end