Diagnosis of Viral infections Flashcards
What is Virus Isolation?
Grow virus in lab, Virus needs to have cells to grow.
What are the advantages of virus isolation?
Amplified.
What are the disadv of virus isolation?
Need to suspect virus, need time, some viruses cannot be cultured.
What is Electron Microscopy? What does it identify about viruses?
Uses negative staining under a microscope. Detects virus morphology.
What are the adv of Electron microscopy?
Used for viruses that can’t be cultured, identify new virus.
What are the disadv of electron microscopy?
Specialised equipment and personell, Low sensitivity.
What is PCR?
Viral nucleic acid detected, and can be amplified.
What are the adv of using PCR?
Very sensitive, doesn’t require live virus, specific.
What are the disadv of using PCR?
Contamination
Outline how an Antigen Elisa is done.
Capture antibody used to detect antigen, then enzyme labelled antibody put it. Substrate changes colour if ELA has bound.
Advantages of Antigen Elisa
Fast, No live virus required, specific
Disadv of Antigen Elisa
No amplification, not specific
What are the three important immunoassays? What do they detect?
Immunofluorescence assay, Immunoperoxidase assay, Immunochromotography. All detect antigen.
How is an Immunofluorescence assay carried out?
Virus detected using antibody with fluorescent particle attached which binds to antigen.
How is an Immunoperoxidase assay carried out?
Elisa on a slide. ELA used to detect antigen, substrate changes colour if it has bound.
