Testing Methods

Question 1

3 testing methodologies in transfusion medicine testing

Answer 1

tube/microplate
gel/column agglutination
solid-phase

Question 2

positive reaction in tube/microplate testing

Answer 2

agglutination as clumps of cells

Question 3

positive reaction in gel

Answer 3

agglutination diffused through the gel column

Question 4

negative reaction in gel testing

Answer 4

pellet at bottom of column

Question 5

cell suspension used in gel testing

Answer 5

0.8%

Question 6

cell suspension used in tube testing

Answer 6

3-5%

Question 7

is there a wash step in gel testing

Answer 7

no

Question 8

is there AHG added to gel testing

Answer 8

no, already in card microtubes

Question 9

gel reaction strength: most of the cells pelleted to the bottom of the tube, with some cells in the bottom half of the gel

Answer 9

1+

Question 10

gel reaction strength: agglutinated red cells all throughout the cell, top to bottom of tube

Answer 10

2+

Question 11

gel reaction strength: most of the agglutinated red cells at the top of the gel, and some of the cells travel to the upper part of the gel

Answer 11

3+

Question 12

gel reaction strength: agglutinated red cells remain at the top of the gel and form a solid band

Answer 12

4+

Question 13

gel reaction strength: layer of red cell agglutinates at the top and a pellet of unagglutinated cells at the bottom

Answer 13

mixed field

Question 14

which side of the gel card should be viewed to interpret results?

Answer 14

both sides

Question 15

how long are gel card reactions stable?

Answer 15

48-72 hours

Question 16

testing method where membranes of red cells have been bound and dried to surfaces of polystyrene micro-titration strip wells

Answer 16

solid phase

Question 17

testing method that employs principle of controlled centrifugation of red cells through a dextran-acrylamide gel and appropriate reagent predispensed in a specifically designed microtube

Answer 17

gel column testing

Question 18

how is solid phase used for antibody screening and identification?

Answer 18

wells pre-coated with red blood cell antigens

Question 19

solid phase indicator cells

Answer 19

red cells with anti-IgG attached to surface

Question 20

what do indicator cells do in solid phase testing?

Answer 20

anti-IgG on indicator cells binds to any IgG antibody from the patient’s plasma that is attached to the cells at the bottom of the well during incubation

Question 21

solid phase positive reaction

Answer 21

adherence of indicator cells to part of all of reaction well surface

Question 22

solid phase negative reaction

Answer 22

button at the bottom of the well