WEEK 6 Platelet Count– Indirect Method PDF

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WEEK 6: PLATELET COUNT–INDIRECTMETHODINDIRECT Compare to direct, it uses dilution of blood using RBC or WBC pipet and Neubauer Chamber  Indirect, the platelets in RBC are counted simultaneously in a blood smear, so there will be no dilution to lyse selectively the RBC. o Platelet and RBC are count...

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WEEK 6: METHOD

PLATELET

COUNT–INDIRECT

INDIRECT  Compare to direct, it uses dilution of blood using RBC or WBC pipet and Neubauer Chamber  Indirect, the platelets in RBC are counted simultaneously in a blood smear, so there will be no dilution to lyse selectively the RBC. o Platelet and RBC are counted together in a blood smear

1. Disinfect the puncture site. 2. After finger puncture, wipe the 1st drop of blood. 3. Place a drop of diluent over the puncture wound. 4. The ratio of blood to diluting fluid should be 1:5. 5. Transfer the mixture into a coverslip and place it on top of a slide. 6. Allow the platelets to settle for 15-45 minutes.  30 mins: stability of diluting fluid 7. Count the RBCs and platelets under OIO until 250 RBCs have been counted.

1. Fonio’s Method Materials:  Microscopic slide  Pipette  Diluting fluid o 14% Magnesium Sulfate  Giemsa or Wright’s stain Procedure: 1. Disinfect the puncture site. 2. After finger puncture, wipe the 1st drop of blood. 3. Place a drop of diluent over the puncture wound. 4. Then press the blood the from the puncture site. 5. The ratio of blood to diluting fluid should be 1:3. 6. Make a smear using the mixture. 7. Allow the smears to dry then stain the smear. 8. Count the RBCs and platelets under OIO until 1000 RBCs have been counted. NORMAL VALUE: 250,000-500,000/ uL

2. Dameshek Method or Wet Method Materials:  Microscopic slide  Pipette  Pipette shaker  Rees Ecker fluid o Brilliant Cresyl Blue (stain) 0.1 gm o 40% Formalin 0.2 mL  preservative o Sodium Citrate 100 mL  To prevent clumping of platelet Procedure:

platelet

count RBC /µL = platelet counted X µL 1000

Wet mount: the RBC tend to concentrate at the edges of the cover slip if wet mount, so you have to count the RBC in the central area. Do not count on the edges so that there will be a false increase in the ratio of Platelet and RBC

3. Modified Dameshek Method 

Uses siliconized medicine dropper to dilute the blood

4. Olef’s Method Materials:  Microscopic slide  Pipette  Diluting fluid o 14% Magnesium Sulfate  Giemsa or Wright’s stain Procedure: 1. Disinfect the puncture site. 2. After finger puncture, wipe the 1st drop of blood. 3. Place a drop of diluent over the puncture wound. 4. Then press the blood the from the puncture site. 5. The ratio of blood to diluting fluid should be 1:5. 6. Make a smear using the mixture. 7. Allow the smears to dry then stain the smear. 8. Count the RBCs and platelets under OIO until 1000 RBCs have been counted  Same principle with Fonio's method

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Confirmation of platelet count can be done on the basis of the occurrence of platelets in the peripheral smear.

25 platelet/OIO field

Thrombocytopenia Adequate Thrombocytosis

Smear estimation Materials:  Microscopic slide  Microscope  Giemsa or Wright’s stain Procedure: 1. Make a perfect blood smear. 2. Stain with Wright stain. 3. Count platelets in 10 OIO fields.

platelet estimate= platelet counted X 2000...