Ab Screen & ID Flashcards
what does an ab screen detect
unexpected allo or auto abs
what kind of sample is used in an ab screen
sera or plasma
what are the 3 testing phases of an ab screen
IS, 37 C, and AHG (Coombs)
what kind of cells are ab screening cells
group O
what kind of ab screen uses pooled ab screening cells
donor testing
what kind of ab screen uses 2 or 3 cell ab screening cell
pt testing
what is the standard ab screening cells used today
3 cell screening
why are 3 cell screening cells used
guarantees homozygosity in the blood groups
what are the 4 currently acceptable ab screening test methods
tube, gel, solid phase red cell adherence, and microwell
what is the standard ab screening test method
tube
what kind of reagent is used in an ab screen
monospecific with anti IgG
what does enhancement media contain in an ab screen
22% albumin, LISS, PEG
what is the normal serum: cell ratio in an ab screen
2:1
what does Coombs control cells contain
IgG coated RBC
what is the function of ab potentiators
reagents that speed up the ag-ab rxn
what does albumin do in enhancement media
reduce the zeta potential between RBCs to increase 2nd stage agglutination
how long do samples have to incubate using albumin enhancement media
30 min to 1 hr
what is the ionic strength of LISS
0.3M
is LISS stronger or weaker than normal saline
stronger
what is added to LISS to prevent RBC lysis at low ionic strength
glycine
what does LISS enhance
ab uptake
what is the incubation time for using LISS
10-15 mins
____ volume of serum and LISS is required
equal
if extra serum is added to LISS what happens
decreases test sensitivity
if extra LISS is added to serum what happens
increases nonspecific pos rxn
what potentiating media is water soluble polymer used to increase AB uptake
PEG