Question

Describe the advantages and disadvatages of using southern, northern, and western blotting.

Answer 1

Southern blotting

Advantages :

- A very effective way to detect a specific DNA sequence in large and complex sample

- detected DNA can be quantified.

- Cheaper than DNA sequencing.

Disadvantages :

- Labor intensive

- Complecx method.

- Time consuming

Northern blotting

Advantages :

- mRNA transcript size can be detected.

- RNA splicing is visible because alternatively spliced transcripts can be detected.

- Quantity and quality of RNA can be verified before proceeding for further thungs.

- Blots can be stored and reprobed when required.

Disadvantages :

- Risk mRNA egradation during electrophoresis which negatively affects quality and quantity measurements.

- Detection with multiple probes is difficult.

- Sensitivity is relatively low compared to that of RT-PCR.

Western Blotting

Advantages :

- Specific interaction of antibody and antigen can be visualized.

- Migration is proportional to molecualr weight so molecular weight measurement is possible.

Disadvantages :

- delicate and time consuming process.

- it causes erroneous bands or no bands due to insufficient transfer.

- primary antibody avilability is crucial.

- it is just a semi-quantitive test, does not give precise values only estimations.