Diagnostic techniques

Question 1

What type of pathogens are cultures mainly done for?

Answer 1

bacteria

Question 2

What can cultures be done on?

Answer 2

blood
swabs from areas
fluids - aspirate, pleural, ascitic, cerebrospinal
tissue

Question 3

What happens to the bacteria in old peoples urine?

Answer 3

gets higher normally

Question 4

What type of pathogens is serology mainly done for?

Answer 4

virus

Question 5

What does serology measure?

Answer 5

antibody (IgM/IgG) in EBV, CMV, syphilis

antigen in Hep B (HBsAG)

Question 6

What does presence of IgM indicate?

Answer 6

pateint has had recent exposure to pathogen

Question 7

What does presence of IgG indicate?

Answer 7

patient has had exposure to pathogen at some point

Question 8

What type of pathogens is PCR mainly done for?

Answer 8

virus

Question 9

What is the action of PCR?

Answer 9

makes direct copied of DNA using heat stable enzyme Taq polymerase (derived from thermus aquaticus)
denatures the DNA, primers bind to denatured DNA, DNA synthesis

Question 10

How can large numbers of PCR be visualised?

Answer 10

gel electrophoresis

Question 11

What can PCR be done on?

Answer 11

blood
swabs
fluids

Question 12

How can PCR monitor an infection?

Answer 12

HIV - negative PCR = controlled
Hep B - negative PCR = controlled
Hep C - negative PCR = cured

Question 13

What is MALDI-TOF?

Answer 13

laser applied to matrix and desorbed into heat
organisms are heated which results in ionisation of ribosomal proteins
ionised proteins travel up the tube and are detected by a mass spectrometer
this produces a finger print that can be detected by data bases

Question 14

What is Whole genome sequencing?

Answer 14

can determine an entire DNA sequence for an organism

and therefore detect things like gene mutations