Shipped February 2014


The challenge was sent to category A, B, C, and C1 laboratories. Participants were presented with the following scenario:

The accessioning bench received a set of 2 blood culture bottles (2 aerobic bottles) collected from an 87 year old male. On observation, both bottles appeared to contain a scant amount of blood. The total volume of blood collected from the patient was only 2 mL, of which 1 mL was dispensed in each blood culture bottle. The phlebotomist described the patient to be very ill with fragile veins and recollection would be very difficult.

Laboratories were asked to select the one option that best describes their protocol.

A. Culture the two vials in the blood culture analyzer for up to 5 days

B. Culture the two vials in the blood culture analyzer for up to 5 days and flag

the vials as inadequate collection volumes.

C. Reject the two vials as insufficient volumes and unacceptable for culture.

D. Immediately forward/refer the two vials to a facility capable of performing advanced direct testing, such as MALDI TOF MS.

E. Sample not applicable to or not normally processed by the laboratory


  1. Low volume blood cultures have a higher risk of yielding a false negative result.
  2. It is inappropriate to reject blood cultures with low blood volume.

Full critique (PDF)

Posted in Clinical Bacteriology Results, critiques