one solid aggregate.
several large aggregates.
medium-sized aggregates, clear background.
small aggregates, turbid reddish background.
W+ tiny aggregates, turbid reddish background.
negative, smooth suspension, no aggregates.
hemolysis. (This must be interpreted as a positive
reaction, and may be graded as complete, or partial.
When both hemolysis and agglutination are observed,
this should be recorded.
1-28. REAGENT RED BLOOD CELLS
(1) Reagent RBCs may be selected from local donors or purchased
commercially. The blood from selected donors is suspended in an
anticoagulant-preservative solution that usually contains sodium citrate, citric acid, and
dextrose, plus various other nutrients or antibiotics. The formulas used by the reagent
suppliers are proprietary. One of the first formulas used for the preservation of reagent
RBCs, Modified Alsever's solution, is still widely used for noncommercial collections.
(2) Most of the commercial cells are marketed, so they may be used without
further preparation; however, because of the interference of a number of the common
additives, washing the cells in amounts sufficient for a day's work, is suggested.
b. For Antibody Detection.
(1) The reagent RBCs used for antibody detection are selected to contain
as many common antigens as possible. The cells are from group O donors and have
been tested for the common antigenic determinants of the Rh, MNSs, Lewis, P, Kell,
Duffy, Kidd, and Lutheran blood-group systems.