1-23. BACTERIOLOGIC PROCEDURES
a. Routine sterility testing is no longer required. Culturing may be desirable
when inspections reveal abnormal donor bloods/components, or when patients have
adverse reactions suspected to have resulted from contaminated donor blood. A good
blood culture technique is: the test shall be performed with a total sample of no less
than 10 ml of blood and a total volume of fluid thioglycollate or thioglycollate broth
medium 10 times the volume of the sample of blood. The test sample shall be
inoculated into one or more test vessels in a ratio of blood to medium of 1 to 10 for each
vessel, mixed thoroughly, incubated for 7 to 9 days at a temperature of 30C to 32C,
and examined for evidence of growth of microorganisms every workday throughout the
test period. On the third, forth, and fifth day, at least 1 ml of material from each test
vessel shall be subcultured in additional test vessels containing the same culture
medium and in such proportion as will permit significant visual inspection, mixed
thoroughly, incubated for 7 to 9 days at a temperature of 30C to 32C, and examined
for evidence of growth of microorganisms every workday throughout the test period.
Subcultures are important because the original culture is usually slightly turbid from the
blood, but the subculture is not. Turbidity is the earliest indication of growth of bacteria.
Subcultures are usually clear if there is no growth.
b. If the sterility studies are done in another laboratory or institution, the medical
director of the blood bank must assure himself that they have been done and reported
to the blood bank adequately. Positive cultures should arouse suspicion of the donor
arm preparation technique and/or component preparation if done using an open system.
If growth is observed in any test vessel, the unit and any components made from it
should be quarantined until additional cultures can be made to rule out faulty culturing
procedures. All positive cultures should be recorded and the blood destroyed.
c. Records of these bacteriologic studies, like other records, must be retained
for at least 5 years and 6 months. Legal requirements for retention of records vary in
different states and the local statutes must be followed if these are longer than 5 years
and 6 months.
1-24. REQUIREMENTS FOR REISSUANCE OF BLOOD
Blood that has been returned to the blood bank shall not ordinarily be reissued
for transfusion until the following conditions have been assured:
a. The container closure has not been penetrated or entered in any manner.
This is to be certain that sterility is maintained.