Question

The phlebotomist was collecting a dermal puncture for a complete blood count (CBC) on a very lethargic, febrile newborn. She had a good flow going, so she filled

the microtainer tube to the top because she knew from experience that often the technicians run the specimen several times to confirm any abnormal results. The CBC
had to be recollected because:

Answer 1

The CBC needed to be recollected because overfilling the microtainer alters the blood-to-anticoagulant ratio, resulting in potentially inaccurate test results and causing problems with laboratory equipment calibrated for specific sample volumes.

Step-by-step explanation:

The complete blood count (CBC) had to be recollected because overfilling a microtainer tube can cause dilution of the blood and negatively impact the ratio of the sample to the anticoagulant. Each microtainer or collection tube is designed to fill with a precise volume of blood, ensuring an accurate ratio of blood to any anticoagulant or additive within. Overfilling can dilute the blood with the anticoagulant, which can result in inaccurate laboratory results. Furthermore, the laboratory equipment is calibrated for specific volumes, so excessive volume might not be properly processed, leading to the need to recollect the sample.