Reagents and Methods for Testing in the Blood Bank (P)

Question 1

What are the basic grps of blood bank rgnts?

Answer 1

1) Rgnts that contain RBCs w/ sp Ag
2) Antiglobulins
3) Potentiators

Question 2

What are the fxns of antiglobulins?

Answer 2

These are rgnts that detect IgG and complement on RBCs

Question 3

What are the fxns of potentiators?

Answer 3

1) These are rgnts that enhance Ab detection

2) Primarily, these rgnts are used to test pts and donors sxs before pt is transfused

Question 4

What are the tests done on RBCs?

Answer 4

1) ABO / Rhesus typing

2) Direct Coombs’ test

Question 5

What are the tests done on serum?

Answer 5

1) Ab screening
2) Ab identification
3) Compatibility testing

Question 6

Where are ABO anti-sera used?

Answer 6

These are used in ABO typing

Question 7

What is the fxn of Anti-A and Anti-B?

Answer 7

These are used to identify a persons blood type

Question 8

What is the principle / mechanism done by anti-sera?

Answer 8

These anti-sera are directed towards sp Ag on the surface of RBCs. Agglutination occurs when Anti-A is added to cells of a person w/c has A Ag, hence, that person is blood type A.

Question 9

What is forward typing?

Answer 9

It is the addition of commercial antisera to cells

Question 10

Rh anti-sera is also called as what?

Answer 10

Anti-D

Question 11

Rhesus blood grp system consists of many diff what?

Answer 11

Many diff Ags

Question 12

Among the diff Ags present in the Rhesus blood grp system, what Ag is the most significant?

Answer 12

D Ag

Question 13

What are the purposes (or actions) of D Ag?

Answer 13

It is able to cause:

1) Serious hemolytic rxn
2) Hemolytic Disease of Fetus and Newborn (HDNB / HDN) (HDFN)

Question 14

What is the requirement when doing ABO typing?

Answer 14

The blood should also be typed for the D Ag (Rhesus type)

Question 15

Where are rgnt cells used?

Answer 15

In reverse typing

Question 16

Rgnt RBCs are used as part of what?

Answer 16

These cells are used as a part of ABO typing procedure

Question 17

What is the principle or mechanism of reverse typing?

Answer 17

Rgnt cells are tested w/ pt’s serum to detect the presence of Abs w/c the Ag (from the pt’s blood type) lack

Question 18

What is the purpose of reverse typing?

Answer 18

It is used as confirmation for the forward typing procedure

Question 19

True or False

Both forward and reverse typing are done concurrently

Answer 19

True

Question 20

What is the meaning of AHG?

Answer 20

Anti- human globulin

Question 21

What is AHG?

Answer 21

It’s an antisera that contains Abs directed against human globulins

Question 22

What are the exs of human globulins that are directed upon by AHG?

Answer 22

1) IgG

2) Complement

Question 23

What are the 2 basic categories of AHG?

Answer 23

1) Monospecific

2) Polyspecific

Question 24

What are fxns of AHG?

Answer 24

It is used in many testing procedures such as:

1) Cross matching
2) Blood typing
3) Autoimmune diseases testing

Question 25

What is the fxn of polyspecific AHG?

Answer 25

It is used in direct antiglobulin testing to test for the attachment of IgG / complement on the surface of RBCs

Question 26

What are the components of polyspecific AHG?

Answer 26

1) Anti-IgG | 2) Anti-C3

Question 27

What is the fxn of monospecific antisera?

Answer 27

To differentiate bet the IgG and C3 coated on RBCs when direct antiglobulin test is (+)

Question 28

Coombs' control cells are also referred to as what?

Answer 28

Check cells (cc)

Question 29

What are the fxns of cc?

Answer 29

1) This is a rgnt used by the blood bank as a control system when the AHG is (-) 2) It converts (-) result into (+) result 3) These basically checks to ensure the procedure was done correctly

Question 30

What are cc?

Answer 30

These are commercially preped grp O (+) human RBCs coated w/ IgG Abs

Question 31

*What is the process (or steps) in relation to the utilization of cc?

Answer 31

1) Add Coombs' control cells to any (-) AHG test 2) Centrifuge 3) Examine for agglutination

Question 32

What is the result if after addition of cc, the rxn does not turn into (+)?

Answer 32

The test test is considered invalid

Question 33

What are the causes of invalid test because the rxn after addition of cc, did not turn (+)?

Answer 33

Either: 1) No AHG was added 2) The cells were inadequately washed 3) The AHG is expired

Question 34

What are the fxns of screening cells?

Answer 34

1) These are used to detect Abs rather than ABO Abs in a person's serum 2) These are used to detect Abs that might have been produced as a result of previous transfusion or pregnancy

Question 35

What type of screening cells are used?

Answer 35

Grp O cells

Question 36

Why are grp O cells used?

Answer 36

Because they lack any ABO Ag on their surface. Therefore, will not react w/ A and B Abs

Question 37

What is the characteristic of grp O cells?

Answer 37

They come in sets of 2 - 3 vials

Question 38

Each vial (present in grp O cells) can be from a what?

Answer 38

Single donor or pooled donors

Question 39

What is the fxn of the vial that came from single donors?

Answer 39

They are used for persons who are about to receive transfusion

Question 40

What is the fxn of the vial that came from pooled donors?

Answer 40

They can be used for donor testing

Question 41

What is the characteristic of each vial (for grp O cells)?

Answer 41

Each set of vial comes w/ sheets of papers called anti-gram

Question 42

What is the purpose of anti-gram?

Answer 42

These shows the type of Ag present on each screening cells

Question 43

Panel cells are same w/ what cells?

Answer 43

They are same w/ screening cells

Question 44

Even though that panel cells and screening cells are the same, there is still a difference present, what is this difference?

Answer 44

Screening cells come in vials of more than 10

Question 45

What is the fxn of panel cells?

Answer 45

These are used for identifying Abs in Ab panel procedure

Question 46

What is the component of each lot of panel cells?

Answer 46

Each lot of panel cells also has an anti-gram w/ antigenic profiles of each vial

Question 47

What is the fxn of potentiators?

Answer 47

These assists in the attachment of an Ab to the sp Ag on the RC

Question 48

What are the exs of potentiators?

Answer 48

1) Bovine albumin 2) Low-ionic strength saline 3) Polyethylene glycol 4) Enzymes

Question 49

What is the fxn of bovine albumin?

Answer 49

It is used during incubation

Question 50

What is the characteristic of low-ionic strength saline?

Answer 50

It is what commercial test cells are in

Question 51

What is the fxn of polyethylene glycol?

Answer 51

It concentrates Ab

Question 52

What are the exs of enzymes that acts as potentiators?

Answer 52

1) Ficin | 2) Papain

Question 53

What is the fxn of enzymes (that act as potentiators)?

Answer 53

These reduces (-) charge

Question 54

What are the Abs that are enhanced by enzymes (w/c acts as potentiators)?

Answer 54

1) Rh | 2) Lewis

Question 55

What Abs are destroyed by enzymes (w/c acts as potentiators)?

Answer 55

1) Duffy 2) M 3) N 4) S

Question 56

What are lectins?

Answer 56

These are seed extracts that have Ab specificity

Question 57

What is the characteristic of lectins?

Answer 57

They do not contain Abs, but instead they contain proteins that react similarly to Abs

Question 58

What is the fxn of lectins (in relation for them to not contain Abs, but instead they contain proteins w/c react similarly to Abs)?

Answer 58

Hence, they are used to identify certain blood grp Ags when they bind to CHO determinants of the Ag resulting in agglutination

Question 59

What are the exs of lectins?

Answer 59

1) Dolichos biflorus 2) Ulex europeans 3) Vicia graminea 4) Iberis amara

Question 60

What is the fxn of Dolichos biflorus?

Answer 60

It binds A1 Ag

Question 61

What is the fxn of Ulex europeans?

Answer 61

It binds H Ag

Question 62

What is the fxn of Vicia graminea?

Answer 62

It binds N Ag

Question 63

What is the fxn of Iberis amara?

Answer 63

It binds M Ag