Application:
• Use of PCR to detect different strains of influenza virus
Influenza is caused by an RNA virus that can rapidly mutate to exist as distinctive serotypes (i.e. different strains exist)
- These strains will have different glycoprotein antigens and hence engender different antibody responses
- Identifying the specific strain of influenza virus in an infected individual will help in the selection of optimal drug treatments
Different strains of influenza can be detected using a modified PCR protocol
- Amplification of the virus requires the conversion of its RNA sequences into cDNA (reverse transcription via RT-PCR)
- Because several different strains of the influenza virus exist, appropriate primers need to be selected to reflect this range
Specific strains of influenza virus can be detected using molecular beacons that target sequences unique to a given strain
- A molecular beacon is a hairpin-shaped nucleotide sequence with an internally quenched fluorophore molecule
- When the beacon anneals to a complementary target sequence, the hairpin unfolds and fluorescence is restored
- Hence, different strains of influenza virus can be detected following RT-PCR amplification according to fluorescence
Detecting Influenza Virus Strains with RT-PCR and Molecular Beacons
