The DISPETTE 2 is a convenient, reliable and safe disposable Erythrocyte Sedimentation Rate (ESR or Sed Rate) test kit manufactured in Switzerland. Its contents provide operators the necessary instruments to efficiently and accurately make determinations through a technique correlating directly with the Westergren method.
The DISPETTE 2 (FH1600/FH1650) features the following improvements from the original Guest Scientific DISPETTE 1 (FH1500)System:
- “Triple plug” tip design on top end of DISPETTE Pipette provides a unique protective barrier from accidental overfilling of the pipette tube and spillage of blood
- Pre-filled reservoirs ensure the correct dilution following recommended Westergren ESR method when 1mL of EDTA blood is added
- Pierceable reservoir cap provides greater tactile feedback during pipette insertion and eliminates the need to remove the cap before insertion, improving safety
- Restricted end of reservoir acts as an extra safety feature — slows downward movement of the tube during insertion and providing a buffered stop
Pre-citrated mixing/filling reservoir - Features
1 Pierceable cap
There is no need to remove the mixing/filling reservoir cap to insert the DISPETTE tube. Simply pierce the special membrane in the cap with the end of the DISPETTE and carefully push to the bottom of the reservoir. This action will fill the DISPETTE with the blood/diluent mixture.
2 Enlarged mixing chamber
Mixing the blood sample with anticoagulant or diluent (citrate or saline) is critically important to produce reproducible ESR results: The International Council for Standardisation in Haematology (ICSH) recommend that a tube with at least 20% airspace above the sample mixture should be completely inverted (180° and back) with the air bubble travelling from end-to-end at least eight times. (1) The enlarged mixing chamber of the DISPETTE 2 filling reservoir enables such correct mixing, thus improving accuracy and reproducibility of results.
3 Fill line
The fill line is formed 1.5mm above the faint line of the sealing ring where the conical base of the mixing chamber meets the top of the filling reservoir. This marker enables the operator to fill accurately from a transfer pipette, syringe or directly from a blood sample tube without the need to measure the amount.
4 Sealing ring
This ensures easy, piston-action, filling of the DISPETTE tube.
5 Restricted End
This extra safety feature provides a buffered stop to the downward progress of the DISPETTE indicating that it is near to its final position and acting as a reminder that the tube must be pushed fully to the bottom of the reservoir.
6 Pre-filled with diluent
The DISPETTE 2 mixing/filling reservoir is pre-filled with 0.25 ml 3.2% Trisodium Citrate or 0.9% saline, to ensure the correct dilution of blood sample following the Westergren ESR method (2) when 1 ml of blood sample is added.
More safety features
Westergren standard ESR tube
Triple protection overflow chamber
This safety feature has been designed to accommodate accidental overfilling of the mixing/filling reservoir. The unique grommet, cotton plug, space, grommet configuration buffers the upward force of the blood sample should too much pressure be used in filling.
Westergren standard pipette dimensions
The widely ranging types of ESR tubes that are available today underline the necessity for standardisation in this frequently requested laboratory test. The increased mobility of patients has further led to the need for comparability of measurements between laboratories. The original Westergren pipette dimensions were adopted by the International Committee for Standardisation in Haematology (ICSH) for their reference ESR method in 1973 (3) In 1993 they recommended that the pipette should be colourless, circular and of sufficient length to give a 200mm sedimentation scale. The scale should comprise clearly marked lines numbered from 200 at the bottom up to 0 in divisions of 1 mm. The pipette diameter should be not less than 2.55mm and the bore constant (within 5%) throughout its length (1). This paper went on to suggest the use of an undiluted blood sample as the reference method to which all routine methods should be standardised. However this complicated procedure proved to be confusing and the most recent ICSH publication (2011) states that the reference method for measurement of the ESR should be based on the Westergren method and goes on to indicate that diluted blood samples (blood to diluent 4 : 1) should be used. (4) In the USA the Clinical Laboratory standards Institute (CLSI) have also adopted the Westergren Method as being the method of choice.(5) The Dispette 2 pipette and filling reservoir have been designed to conform to the Westergren dimensions and provide the correct dilution for the method.
After the ESR results have been recorded the whole Dispette and filling reservoir assembly is discarded without separation thus providing an extra measure of safety for the operator and disposal staff.
The Dispette 2 is available as:
DISPETTE 2 saline (FH1600)
The DISPETTE 2 saline pack contains 100 tubes and reservoirs prefilled and ready to use with a 0.9% Saline diluent.
Please note: This package does not include any stand. It can be ordered separately (DISPETTE leveling stand FH1705).
DISPETTE 2 Saline
DISPETTE 2 Citrate
DISPETTE leveling stand
ESR stand w/ leveling screws
1 ICSH Recommondations for Measurement of Erythrocyte Sedimentation Rate. J. Clin. Path. 1993; 46: 198-203.
2 Westergren A. Studies of the Suspension Stability of the Blood in Pulmonary Tuberculosis. Acta.Med.Scand 1921; 54: 247-82.
3 ICSH Reference Method for Erythrocyte Sedimentation Rate (ESR) test in human blood. Br. J. Haematol. 1973; 24: 671-3.
4 Jou, J.M., Lewis, S.M., Briggs, C., et al. ICSH review of the measurement of the erythrocyte sedimentation rate: Int. J. Lab Haem, 2011: 33,125-132.
5 Clinical and Laboratory Standards Institute (CLSI), Procedures for the Erythrocyte Sedimentation Rate Test; Approved Standard-Fifth Edition. H02-A5, May 2011. ISBN 1-56238-754-5.