Exam III Flashcards
What is the affect of albumin on the zeta-potential?
(usually 22% bovine albumin) acts to decrease the zeta-potential, allowing red cells to move closer to one another and allowing IgG to bridge the gap between them; all of this facilitates the antigen-antibody reaction
Which immunoglobulin class is able to “bridge the gap” between red cells in an antigen-antibody reaction, and why is this?
IgM; it’s a larger molecule and so can far more easily close the distance between cells; it also has more antigen binding sites
What is the optimum reaction temperature for IgM?
22*C or ambient (immediate spin phase)
What is the optimum reaction temperature for IgG?
37*C
What immunoglobulin class to ABO and Lewis antibodies belong to?
IgM
What immunoglobulin class to Rh antibodies belong to?
IgG
What is LISS and what effect does it have on antigen-antibody reactions?
low ionic strength solution (0.2% NaCl); reduces the ionic strength of reaction media to decrease the zeta-potential
What are the four enzymes used in blood bank testing and what effect do they have?
ficin, papain, bromelain, and trypsin; the can enhance the reactivity of some antigens, while destroying the reactivity of others; they also reduce zeta-potential by removing glycoprotein from the surface of red cells which makes them more hydrophobic, therefore allowing more access for antibody binding
What antigens are enhanced by enzyme treatment?
Rh, Kidd, P1, Lewis, and Ii
What antigens are destroyed by enzyme treatment?
Duffy, MNSs
What is meant by dosage, and what antigens demonstrate this phenomenon?
weak expression due to heterozygous inheritance of red cell antigen; MNSs, Kidd, Lutheran, Duffy, and Rh (Cc, Ee)
What is anti-A,B?
cross-reactive antibody found in type O serum; also agglutinates red cells of infrequent A subgroups, especially Ax
