Identify Bacteriophage for Treatment of Mrsa by Matching Dna Sample Using Dna Fingerprinting

IDENTIFY BACTERIOPHAGE FOR TREATMENT OF MRSA BY MATCHING DNA SAMPLE USING DNA FINGERPRINTING

Introduction

We aim to find out the identity of unknown bacteriophage strain (sample E) which made MRSA die. MRSA (Methicillin-resistant Staphylococcus aureus) is a bacterium that difficult to treat and most commonly colonies under the anterior nares(Yan M et al.,2013). By matching DNA samples (X,Y,Z)  collected from the three most abundant bacteriophage strains places using DNA fingerprinting, we can confirm the identity of sample E. DNA fingerprinting uses restriction endonuclease, or restriction enzymes to cut DNA molecules at or near specific recognition nucleotide sequences known as restriction sites (Roberts RJ,1976). Each restriction endonuclease recognises a particular short DNA sequence and cuts DNA into small fragments. Gel electrophoresis is used to separate DNA according to size of fragments (Kryndushkin DS et al, 2003). An electric current is applied along the gel so the negatively charged fragments will move. As restriction endonuclease is sequence specific result in different cutting position, the different sized fragments give a comparable pattern that can be visualised under UV light after using dye.

Aim

To find out the identity of sample E by distinguishing DNA sample from different location using restriction endonuclease and gel electrophoresis techniques.

Materials and Methods

Refer to BIOL 1004 Lab Manual,2016 (Practical 1- DNA fingerprinting, pp.24-25).

5μl of 2X restriction buffer and 2μl of restriction enzyme were added into each sample. Each sample was spun down by pulsing in a microcentrifuge and incubated. After 5μl of loading dye was added into sample, 15μl of each sample was loaded into separate well in agarose gel and 5μl ladder was loaded separately. The gel was connected to power supply at 100 volts. The DNA bands were viewed under UV light. However, there are deviations: the samples were incubated for longer time(30 minutes) and the gel ran for longer time(42 minutes) at 100 volts.