Quantitative determination
Direct Method
Store at room temperature.
For “in vitro” diagnostic use only.
PRINCIPLE
This method has been developed for the counting of platelets
using normal laboratory equipment and whole blood samples.
The tecnique involves a quick lysis of red cells by the
improved diluting in which an effective antiaggregating agent
has been added to avoid the shortcomings of conventional methods.
REAGENT PREPARATION AND STABILITY
The reagent is ready to use.
Stable when protected from light and stored at room
temperature until the expiration date on the label.
Do not use reagents over the expiration date.
SAMPLES
Venous blood collected into K3 – EDTA
MATERIALS
-Thoma counting chamber or similar.
- Microscopy.
PROCEDURE
50 x 1.98 mL
1. Expell into the plastic disposable tube 20 µL (0.02 mL) of
blood cells. Mix well by repeated inversion manually or
mechanically for 4-5 minutes. Do not shake.
2. Fill the chamber of Thoma by placing the tip of pipette
are one of the open ends of the chamber. If air bubbles
are present, clean again and refill the chamber.
3. Allow to stand for 15 minutes in order to ensure
sedimentation of the platelets in closed Petri dish kept humid.
4. Counting. Count total number of platelets of the whole chamber (1 mm2 ).
Platelets will appear as small refractile bodies under the
X40 objective and the X10 eyerpiece.
50 mL
1. Pour into a disposable test tube enough volume to
perform the test needed (1mL / Test). Never introduce
the red cell pipette directly into a Platelet Counting Fluid
bottle.
2. Fill a red cell pipette rapidly with whole blood taken in the
way described, to the 1 mark.
