A Phlebotomist is sent to a patient at the cardiac care unit (CCU) of Korle-bu Teaching Hospital to collect a blood sample for fasting blood sugar (FBS). The patient has tiny veins, so he selects a small grey –top tube and proceeds to collect the specimen. While blood is filling the tube, the patient’s nurse tells him that the Physician has added a potassium test to the request. He finishes collecting the FBS specimen, grabs a small-volume lavender/violet top-tube, and proceeds to collect the potassium specimen.​