QUANTITATIVE BUFFY COAT (QBC)
QBC tube is used for malaria parasite test; it is a small capillary tube, which is internally coated with a fluorescence dye at one end and anticoagulant at the other end. It has blue fill lines and white label lines.
Principle Of Quantitative Buffy Coat
The QBC test is a method for identifying the malaria parasite in blood, it is a high glass hematocrit pre-coated internally with acridine orange stain and potassium oxalate. The tube which contains the blood sample is centrifuged at 12,000 revolutions per minutes for 5 minutes. The QBC tube is placed on the tube holder and examined under the microscope.
Immersion oil in Quantitative Buffy Coat
Immersion oil; is oil dropped on the QBC malaria tube before viewing under a microscope; when light passes through oil, it does not scatter but converges and it is used when using high magnification.
- Patient’s blood is collected into EDTA tube which is given a laboratory serial number.
- The EDTA tube is placed on a mixer for mixing.
- After which QBC malaria tube is filled with blood using the anticoagulant end by capillary action, the tube is filled up to the second blue fill line then wiped with gauze.
- The tube is then closed with a stopper at dye end and a floater inserted at the anticoagulant end to help keep plasma separated from serum after centrifuge.
Malaria parasite results
The parasite can be seen as bright specks of light they appear in a ring form looking like an engagement ring if there are 0-20parasites seen within fields, it can be said to be plus one(+1), 20-100 can be said to be plus (+2) while l00 and above is plus (+3).