TM Quality, Ag Frequencies

Question 1

Quality Control

Answer 1

• Activities that ensure quality of the product - In the lab,
  results are our product, so QC ensures reagents, equipment,
  procedure (including personnel etc.) are working to generate a
  quality result

Question 2

Policy

Answer 2

Rules and guidelines adopted by the organization that drive processes and procedures

Question 3

Process

Answer 3

The “big picture” outline that depict the various tasks and
procedures from INPUT TO OUTPUT

Question 4

Procedure

Answer 4

Step-by-step instructions to complete a particular task

Question 5

Does sensitivity relate to false pos OR false neg results ?

Answer 5

ensures true pos/ minimizes false pos
- a highly sensitive test means less false negative results; thus fewer cases of true pos are missed

Question 6

Does specificity relate to false pos OR false neg results ?

Answer 6

ensures true neg/ minimizes false neg
- a highly specific test means that there are less false positive results

Question 7

Describe a good POSITIVE antiserum control

Answer 7

• heterozygous cell that has less Ag for higher sensitivity = true pos

Question 8

Describe a good NEGATIVE antiserum control

Answer 8

• homozygous cell
  should not have the Ag = true neg

Question 9

Over centrifugation: false pos or neg ?

Answer 9

False pos; RBCs stuck on tube (non-specific binding)

Question 10

DATs on clotted specimen: false pos or neg ?

Answer 10

False pos

Question 11

Delay between washing and adding AHG: false pos or neg ?

Answer 11

False neg; RBCs dissociate towards equillibrium

Question 12

Poor washing: false pos or neg ?

Answer 12

False neg; unbound IgG neutralizes AHG

Question 13

Why may Coomb’s control tube also be negative in PEG IAT ?

Answer 13

Coomb’s control did not work:
- AHG not added, expired, not stored properly
- Skipped wash step
- Wrong incubation temp
- Overshaken RBC = hemolysis
- Wrong cells added
- Under-centrifuged
- Contaminated saline