Multiple Displacement AmplificationBy : Faizan Saleem

Introduction Multiple displacement amplification is a non-pcr based

amplification technique.

It does not require multiple cycles for the amplification of template DNA.

 An specific type of DNA polymerase is required i.e Φ29 DNA polymerase.

Even minute quantity of DNA from single cell can be amplified with high fidelity rate.

Whole amplification process requires a constant temperature of 30°C .

Φ29 DNA polymeraseΦ29 DNA polymerase is obtained from bacteriophage

Φ29.

It has been extensively used in the field of molecular biology.

It comprises of two domains: A C-terminal domain (polymerase domain). An N-terminal domain (3'-5’ exonuclease domain).

As compared to other type of polymerases, It has a higher processitivity and proofreading ability.

How it Works:

Hyper Branched Structure

Pros and Cons

Pros : It provides higher processitivity , More than 70 kb

of DNA can be obtained.

Higher fidelity rate,  Φ29 DNA polymerase has a 3’–5' proofreading activity that provides  amplification error rate to 1 in 106−107 bases compared to conventional Taq polymerase.

DNA from a single cell can be used for amplification.

Does not require a thermo cycler .

Cons :Over amplification of a certain region may occur.

Primer dimer formation is common occurrence.

Allelic Dropout may occur in case of heterozygous sample.

Requires constant temperature.

Applications of MDA Single cell genome sequencing.

Forensic Analysis.

SNP genotyping

Southern Blotting etc.

Recent Work Done :