Laboratory studies

Question 1

Polymerase chain reaction

Answer 1

Used to amplify a desired fragment of DNA

1. Denautration
2. Anealing: excess DNA primers anneal to specific sequence
3. Elongation

Question 2

Southern blot

Answer 2

DNA sample enzymatically cleaved into smaller peices and blotted on a gel through electrophoresed

Question 3

Northern blot

Answer 3

RNA sample is electrophoresed, useful for studying mRNA levels, which are reflective of gene expression

Question 4

Western blot

Answer 4

Sample protein is separated via gel electrophoresis and labelled antibodies are used to bind to relevant protein

Question 5

Southwestern blot

Answer 5

Identifies DNA-binding proteins using oligonucleotide probes

Question 6

Enzyme-linked immunosorbent assay

Answer 6

Used to detect presence of either a specific antigen or specific antibody

Direct: uses a test antibody to see if a specific antigen is present

Indirect: uses a test antigen to see if a specific antibody is present

Used in many laboratories to determine whether a particular antibody such as anti HIV is present in a patient’s blood

Question 7

Fluorescence in situ hybridization

Answer 7

Fluorescent DNA or RNA probe binds to specific gene site of interest on chromosomes.

Used for specific localization of genes and direct visualization of anomalies such as microdeletions at molecular level when deletion is too small to be visualized by karyotype

Question 8

RNA interference RNAi

Answer 8

dsRNA is synthesized that is complementary to the mRNA sequence of interest. When transfected into human cells, dsRNA separates and promotes degradation of target mRNA and therefore indirectly knocking down specific targeted gene expression