A platelet count blood test is important for the calculation of platelet in the blood. Like other blood tests Hb, CBC, LFT (liver function test), RFT (Renal function test), and platelet can be counted by two methods.

• Manual Method
• Automated method

Note: Both methods are used but the manual or visual method is more reliable than an electronic particle counter.

Requirements for Platelet count blood test

The following five are the requirements for platelet count blood tests.

1. Platelet Diluting Fluid: 1% ammonium oxalate is used plt diluting fluid. It is 1% ammonium, oxalate is prepared by adding 1 gram of ammonium oxalate with 100 ml water.
2. Improved Neubauer chamber:
3. WBC pipette
4. Microscope
5. Petri Dish with moist cotton or tissue paper.

How to count platelets in the Neubauer chamber?

1. First, prepare the 1:20 of blood with dilution.
2. Fix the coverslip on the improved Neubauer chamber, then charge it.
3. Now cover the chamber in a Petri dish (To avoid the drying of the sample) for 15 to 20 minutes.
4. After 20 minutes, now place the Neubauer chamber on the stage of the microscope and read at objective 40 x.
5. Count the small high refractile discs in the central large square area of the Neubauer chamber.

Note: At least 200 platelets should be counted.

Calculation of platelet count blood test

• Central large area: 1 mm2
• The volume of 1 large square area: 0.1 mm
• Dilution: 1 in 20
• Number of platelets: N

Platelet counting Formula: N* 20 * 10 ⁹

Platelet count normal range

The platelet normal range for males and females is 150 to 340 * 10⁹ .