Special Operations Forces Medical Handbook

8-53

j. Ream the plug with an applicator stick and decant the supernatant.
CAUTION: Do not allow debris or ethyl acetate to contaminate the sediment.

2. Perform the microscopic examination.
   a. Transfer 1 drop of the sediment to a glass slide.
   b. Add 1 drop of Lugol’s iodine and cover with a coverslip.
   c. Scan the whole slide on low (10x) power.
   d. Identify using high-dry (40x) objective. Scan at least 75 fields under high dry.


3. Record and report the results on the laboratory request form.
   a. If organisms are recovered, report by genus and species.
   b. If no organisms are seen, report “No ova parasites seen.”

Lab Procedure: Microhematocrit Determination

18D Skills and Training Manual

When: To measure the percentage of red blood cells in total blood volume.

What You Need: A control; a logbook; either a microhematocrit centrifuge (calibrated to 10,000 rpm), with
a microhematocrit reader, sealing putty, and capillary tubes; or a Compur M1100 minicentrifuge with capillary
tubes and operator’s manual; a laboratory request form.

What To Do:
NOTE: The hematocrit is the ratio of red blood cells to plasma expressed as a percent of whole blood.

1. Microhematocrit Centrifuge/Reader Method, if applicable.
   a. Prepare the blood specimen collected in EDTA tubes.
   NOTE: If blood was collected in capillary tubes, remove them from the reverse side of the laboratory
   request form and proceed to step 1b.
   (1) Mix the control or specimen by gently inverting the tube several times before removing the
   stopper.
   (2) Fill two capillary tubes 3/4 full without bubbles.
   NOTE: The test should be performed in duplicate to correlate the results and to balance the
   centrifuge.
   (3) Seal the tubes by plunging the dry ends into a putty pad.
   b. Centrifuge the capillary tubes.
   (1) Put one tube opposite the other with the sealed ends toward the rubber gasket.
   (2) Centrifuge the tubes for 5 minutes
   c. Read the results by using the microhematocrit reader.
   (1) Place the tube in the groove of the plastic holder with the sealed end toward the center and the
   black index line intersecting the red blood cell-clay interface.
   (2) Match the red vertical line on the plastic holder with the numeral “100” on the outer circle of
   the microhematocrit reader.
   (3) Rotate the inner circle while holding the outer circle stationary until the black spiral indicator line
   matches the plasma/air interface line within the tube.
   (4) Rotate both the inner and outer circles of the reader clockwise simultaneously until the black
   spiral indicator line matches the RBC plasma interface line excluding the buffy coat.
   (5) Run the control and unknown in duplicate.
   (6) Report and record the results in percentage on the laboratory request form and in the logbook.


2. Compur M1100 method, if applicable.
   a. Prepare the blood specimen collected in the EDTA tubes.
   (1) Mix the control/specimen by gently inverting the tube several times before removing the
   stopper.
   (2) Completely fill two M1100 capillary pipets with blood.