This a new method for identifying the malaria parasite in the peripheral blood.
It is fast, easy and claimed to be more sensitive than the traditional thick smear examination.
It involves staining of the centrifuged and compressed red cell layer
with acridine orange and its examination under UV light source.
Method: The tube is a high-precision glass hematocrit tube, pre-coated
internally with acridine orange stain and potassium oxalate.
It is filled with 55-65 micro liters of blood from a finger, ear or heel puncture. A
clear plastic closure is then attached.
A precisely made cylindrical float, designed to be suspended in the packed red blood cells, is inserted.
The tube is centrifuged at 12,000 rpm for 5 minutes.
The components of the buffy coat separate according to their densities, forming discrete bands.
It involves staining of the centrifuged and compressed red cell layer
with acridine orange and its examination under UV light source.
Because the float occupies 90% of the internal lumen of the tube, the
leukocyte and the thrombocyte cell band widths and the top-most area of
red cells are enlarged to 10 times normal.
A negative test can be reported within one minute and positive result
within minutes. is a new method for identifying the malarial parasite in
the peripheral blood.
The key feature of the method is centrifugation and thereby
concentration of the red blood cells in a predictable area of the tube,
making detection easy and fast.
Red cells containing Plasmodia are less dense than normal ones and
concentrate just below the leukocytes, at the top of the erythrocyte
column.
The float forces all the surrounding red cells into the 40 micron space
between its outside circumference and the inside of the tube. Since the
parasites contain DNA which takes up the acridine orange stain, they
appear as bright specks of light among the non-fluorescing red cells.The
tube is placed on the tube holder and examined using a standard white
light microscope equipped with the UV microscope adapter, an
epi-illuminated microscope objective. Fluorescing parasites are then
observed at the red blood cell/white blood cell interface.
Virtually all of the parasites found in the 60 micro liter of blood can
be visualized by rotating the tube under the microscope.
It is fast, easy and claimed to be more sensitive than the traditional thick smear examination.