Diagnostic investigations

Question 1

What are the main types of investigations?

Answer 1

Radiological
Physiological
Pathological

Question 2

What are investigations for?

Answer 2

Diagnosis
Suitability for treatment
Prognosis
Monitoring treatment
Screening

Question 3

What do the lab need to know about the clinical context?

Answer 3

Demographics of patient
Type of specimen
Tests required
Clinical diagnosis
Relevant treatment

Question 4

What are the 3 sources of error?

Answer 4

Pre-analytical - e.g. contamination, wrong tube, mislabelling
Analytical - e.g. machine not calibrated, dilution errors
Post-analytical - e.g. admin error, lack or knowledge or communication

Question 5

What are the 3 features of microbiology?

Answer 5

MCS -

• Microscopy - see it
• Culture - grow it
• Sensitivity - kill it

Question 6

What colour is gram positive staining?

Answer 6

Purple

Question 7

What colour is gram negative staining?

Answer 7

Red

Question 8

What are the two types of gram staining shapes seen?

Answer 8

• Cocci - circular shape

- Rods

Question 9

Give examples of gram positive cocci

Answer 9

Staphylococcus (MRSA)

Streptococcus

Question 10

Give examples of gram positive bacilli (rods)

Answer 10

Bacillus anthracis
Baccilus Cereus
Listeria
Propionobacterium acnes

Question 11

Give an example of gram negative cocci

Answer 11

Neisseria (gohorrhoea)

Question 12

Give examples of gram negative rods

Answer 12

E. coli
Klebsiella
Pseudomonas
Haemophilus

Question 13

Give two examples of gram stain “funnies”

Answer 13

Vibrios - “comma shaped”

Campylobacter - “seagull shaped”