Module 1

Question 1

Types of reagent red cells commonly used in the TM lab

Answer 1

A1 and B cells, Group O cells, Screening cells, Special screening cells, panel cells, IgG-coated and complement coated check cells, and cord cells

Question 2

Murine origin

Answer 2

A mouse is the original host

Question 3

Advantages of monoclonal antibodies

Answer 3

Available in large quantities
Very specific and sensitive
No risk of disease transmission
Little lot-to-lot variability
Production is independent on human sources of antibody
Antibodies are IgM, causing direct agglutination

Question 4

Seeds of dolichos biflorus are a source of:

Answer 4

Anti-A1

Question 5

Seeds of ulex europeus are a source of:

Answer 5

Anti-H

Question 6

Cord cells are routinely used to distinguish:

Answer 6

auto anti-I from other autoantibodies

Question 7

Glycoproteins from plants which show specificity for human red cell antigens are called:

Answer 7

lectins

Question 8

Extract of Dolichos biflorus seeds is used to:

Answer 8

distinguish group A1 from other group A cells

Question 9

Monoclonal antibody production

Answer 9

A small animal is immunized with a purified antigen. The animal produces an antibody in response to the antigen. We make a suspension from the mouse’s spleen (B) cells and incubate the suspension with a suspension of mouse myeloma cells. The B lymphs from the mouse’s spleen fuse with the myeloma cells to form mouse hybridoma cells. These cells grow rapidly and produce antibodies rapidly. Single hybridoma cells are grown in tissue culture where they secrete their specific antibody into the surrounding medium. The antibody is then harvested.

Question 10

Saline reactive antisera contains what class of antibody in what medium?

Answer 10

IgM in a saline medium (may contain 6-8% albumin)

Question 11

Slide and modified tube Rh antisera contains what class of antibody in what medium?

Answer 11

Incomplete IgG in a high-protein medium, usually 22% albumin

Question 12

Antisera reactive by AHG technique contains what class of antibody in what medium?

Answer 12

Incomplete IgG in a saline medium (may contain 6-8% albumin)

Question 13

What temperature do saline reactive antisera react at?

Answer 13

Room temperature

Question 14

What temperature do slide and modified tube Rh antisera react at?

Answer 14

37C

Question 15

What temperature do antisera reactive by AHG technique react at?

Answer 15

37C

Question 16

Titre and avidity are influenced by:

Answer 16

Antigenic strength of the RBC used in testing
Medium in which the RBC are suspended
Concentration of RBC suspension
Temperature

Question 17

How long are pretransfusion testing results valid for?

Answer 17

96 hours from the time of sample collection

Question 18

Why do we wash red cells?

Answer 18

To remove unwanted substances such as antibodies, Wharton’s jelly (on cord samples), soluble antigens, EDTA, free hemoglobin

Question 19

Sources of error in washing red blood cells

Answer 19

Not properly re-suspending cells (shaking) between washings

Losing too many cells when removing the supernatant washes

Question 20

How long do we keep temperature charts in TM?

Answer 20

5 years

Question 21

Incomplete IgG antibodies in a high-protein medium, incubated at 37C and spun. What kind of reagent antisera is this?

Answer 21

Slide and modified tube Rh antiserum

Question 22

IgM antibodies in a saline medium, which react at room temperature (immediate spin). What kind of reagent antisera is this?

Answer 22

Saline reactive antiserum

Question 23

IgG antibodies in saline which require 37C incubation and check cells. What kind of reagent antisera is this?

Answer 23

Antiserum reactive by Anti-human globulin technique

Question 24

What are special screening cells used for?

Answer 24

Used for identification of anti-D due to Rh immunoglobulin