Use of an in vitro biotinylation technique for determination of posttransfusion viability of stored canine packed red blood cells.

OBJECTIVE: To determine posttransfusion viability (PTV) of canine RBC stored for 35 days in an additive solution, using in vitro biotinylation and technetium-99m and chromium-51 (99mTc/51Cr) labeling techniques. SAMPLE POPULATION: 6 random source, adult dogs. PROCEDURE: RBC from dogs were labeled with N-hydroxysuccinimide biotin (NHS-biotin) or 99mTc/51Cr in a crossover design. One unit (450 ml) of whole blood was collected from each dog, processed into packed RBC, and stored for 35 days in an additive solution. The process was repeated at a later date, so that each dog had 2 units stored under similar conditions. Stored autologous RBC were then labeled with either NHS-biotin or 51Cr and reinfused. When 51Cr was used, labeled cells were infused simultaneously with freshly drawn cells labeled with 99mTc. Posttransfusion viability of labeled cells was determined by dividing counts per minute (99mTc/51Cr) or percentage of cells (NHS-biotin) labeled at 24 hours by counts per minute or percentage of cells labeled after infusion. RESULTS: Mean PTV of packed RBC stored for 35 days in an additive system was 80% when determined by biotinylation, 83% as determined by 99mTc/ 51Cr, and 81% as determined by 51Cr alone. CONCLUSIONS: In vitro biotinylation provides an acceptable, nonradioisotopic means of determining PTV of stored canine packed RBC. CLINICAL RELEVANCE: NHS-biotin can be used to determine maximal storage time of canine RBC prepared for transfusion purposes.