virology LT2 Flashcards
What methods were initially used to study viruses in the early days of virology research?
Early studies on viruses were conducted in bacteria, plants, and whole animals, such as mice, rats, and rabbits. Additionally, fertile chicken and duck eggs were employed for studying viral pathogenesis and vaccine efficacy.
How are viruses purified in virology research, and what techniques are used for this purpose?
Viruses are purified through a series of centrifugation steps. Low-speed centrifugation is used to remove cells and large debris, leaving virions in the supernatant. Further purification and concentration can be achieved through higher-speed centrifugation and the use of sucrose or glycerol gradients.
What are the primary techniques used to visualize viruses, and how do they provide different types of information?
Viruses can be visualized using optical microscopy and electron microscopy (EM) techniques. EM techniques include negative staining EM, thin sectioning EM, cryo-EM, and confocal microscopy, each providing unique information about the structure and characteristics of viruses.
How do infectivity assays and chemical/physical methods contribute to counting viruses?
Infectivity assays measure virions that can successfully infect cells and produce infectious progeny, providing a count of biologically active viruses. Inactivated viruses can be quantitated using chemical/physical methods, such as spectrophotometry or serologic techniques, which assess viral proteins or antigens.
What are the key molecular techniques used in diagnostic virology to detect viral nucleic acids?What are the key molecular techniques used in diagnostic virology to detect viral nucleic acids?
Polymerase chain reaction (PCR) and high-throughput sequencing are common molecular techniques used in diagnostic virology to detect viral nucleic acids. These methods enable the identification and characterization of viruses in clinical samples.
