Biochem: lab techniques

Question 1

What are the 3 main steps of PCR?

Answer 1

denaturation, annealing, elongation

Question 2

What do southern blots look at? What type of probe do they use?

Answer 2

DNA sample

DNA probe

Question 3

What do northern blots look at? What type of probe do they use? What are they used to study?

Answer 3

RNA sample
DNA probe
mRNA levels

Question 4

What do western blots look at? What type of probe do they use?

Answer 4

protein sample

Ab probe

Question 5

What does a southwestern blot look at? What type of probe do they use?

Answer 5

DNA binding protein sample (ie/ transcription factor sample)

oligonucleotide probe

Question 6

What are microarrays used for?

Answer 6

to profile gene expression levels of thousands of genes simultaneously
able to detect single nucleotide polymorphisms for a variety of applications (genotyping, forensic analysis, predisposition to disease, cancer mutations & genetic linkage analysis)

Question 7

What do ELISAs test for?

Answer 7

antigen-antibody reactivity

determine whether a particular antibody is present in a patient’s blood sample

Question 8

How does an indirect ELISA work?

Answer 8

uses a test antigen to see if a specific anibody is present in the patient’s blood, a secondary ab coupled to a color generatin enzyme is added to detect the first antibody

Question 9

How does a direct ELISA work?

Answer 9

uses a test antibody coupled to a color generating enzyme to see if a specific antigen is present in the aptient’s blood

Question 10

How does FISH work?

Answer 10

fluorescent DNA or RNA probe binds to specific gene site of interest on chromosomes
used to localize genes and directly visualize anomalies (like microdeletions)
fluorescence=gene is present, no fluorescence=gene has been deleted

Question 11

What is karyotyping used for

Answer 11

to diagnose chromosomal imbalances