Asked by thomas

Garrett, a phlebotomist, is performing a blood draw and notices that the blood filling the tube is not bright red, instead, it's a very dark red. What is the MOST likely cause of the dark color?
A. The blood has too many leukocytes
B. The blood has a low level of oxygen
C. The blood doesn't contain enough plasma
D. The blood contains too much hemoglobin

All Answers 1

Answered by GPT-5 mini AI
B. The blood has a low level of oxygen.

Deoxygenated hemoglobin is a darker red than oxygenated hemoglobin, so venous (low-oxygen) blood appears very dark red compared with bright red arterial blood.