Practical Flashcards Preview

ZZBOD - undergraduate year 2 pathology > Practical > Flashcards

Flashcards in Practical Deck (32):
1

Antistreptolysin O titration

A test in which patient serum is added to RBCs and streptolysin; in patients with a strep. pyogenes infection, there are anti-streptolysin antibodies present which inhibit RBC lysis.

2

The ELEK plate

Tests for C. diptheriae toxins. Vertical paper has antiserum; precipitate indicates positive result.

3

Albert's method.

A method of staining of Corynebacterium diptheriae to show polyphosphate granules.

4

Hot malachite green

used to stain for spores

5

Gas gangrene

Caused by C perfringens

6

B. fragilis

Important in wound infection, after appendicitis, septicaemia after injury. Sensitive to metronidazole.

7

Elisa

Quantify Ab or Ag

8

Reverse passive haemagglutination

Chemically bind RBCs with antibody; titre with sample; if it agglutinates, then antigen present. Used to check for microbial antigens.

9

Agglutination inhibition

Anti-HCG Ab binds HCG coated latex beads unless it has been previously bound by HCG in the urine. A positive test is where there is no precipitate, because hCG from the urine not the beads binds the antibodies.

10

Gel precipitation - several separate lines present

More than one antigen, more than one Ab

11

Plaque forming cells

Detects lymphocytes secreting Ab; if the person has been exposed to the antigen before, there will be areas of lysis in surround as will produce Ab leading to complement lysis

12

Complement fixation test - minimal haemolytic dose.

Titrates haemolytic activity of complement; the highest dilution that gives 100% lysis is 1 minimal haemolytic dose.

13

Complement fixation test

Determine how much Ab will form enough complexes to inactivate all complement. Use titred complement. Controls = complement + sera, complement + test antigen. Positive test is no lysis.

14

Salmonella classification

Use latex beads bound to anti-sera against the surface glycoprotein O or H antigens; clumping is a positive result

15

Nagler reaction

Positive for Cl. perfringens.

16

Lancefield grouping

Agglutination = positive result

17

Thrombus with laminations

New

18

Venous thrombus without laminations

old

19

Troponin 1 and MB creatine kinase

Usually only found in cardiac myocytes.

20

Poisson distribution

Px = (M to the x times e to the -m)/x!
Where m = the moi and x = number of time for target to be hit. moi = phage per cell

21

In immunoelectrophoresis, what moves to the positive pole?

Albumin (acidic)

22

In immunoelectrophoresis, what moves to the negative pole?

gamma globulins.

23

In immunoelectrophoresis, what moves to the positive pole, but is generally central?

transferrin

24

the Coombs test used for...

Used to test for haemolytic disease of the newborn.

25

the Coombs test technique

Anti-RhD is bound to RBCs. Other Abs are in serum. Wash cells to get rid of other Abs, then add Anti-human Ab; this binds Fc or Anti-RhD Ab, causing INDIRECT AGGLUTINATION.

26

Influenza haemagglutination assay

Influenza virus directly agglutinates fowl RBC

27

Virus neutralisation assay

Finds highest dilution of serum which will neutralise the virus (by Ab binding); demonstrates infection.

28

Ent faecalis

Very tiny colonies, chains of gram +ive cocci. Use catalase test to differentiate from staph epidermidis. Also lactose fermenting (MAC red, CLED yellow)

29

Strep pyogenes; further tests

Always mention Lancefield grouping for cell wall polysaccharide; should be Lancefield group A

30

Strep. pneumoniae

chains of gram +ive cocci; volcano shaped colonies. Incomplete haemolysis.

31

Strep viridans

Normal mouth flora.

32

follow up test for E.Coli

MacConkey plate or API test