Calibration & Controls

Guidance

The DISPETTE system qualifies as a manual (nonautomated) ESR test and as such is granted waived status by the CLIA. The DISPETTE system is manufactured to Westergren dimensions and current ICSH and CLSI specifications.1,2 The CLSI states that the (Westergren) ESR procedure cannot be calibrated and is ‘inherently quite stable’.2 A quality assurance program should ideally detect variables, which, amongst others, include errors in the dilution step, poor temperature control, vibration and verticality. Using control specimens, in itself, will not solve these problems, but will, if used in a comprehensive quality assurance program, alert to the existence of potential problems.2

Operators need to ensure that the DISPETTE pipette assembly is set up correctly:

  • The ESR pipette must be held motionless and in upright position (± 2 degrees off the vertical)2
  • The test must be performed at constant temperature (±1°C) within the range of 18°-25°C1,2
  • The test must be protected from sunlight, draughts and vibration throughout the entire sedimentation period1,2
We recommend using the DISPETTE leveling stand (order code: FH1705), as it, when set up correctly, minimizes errors due to temperature control and verticality, by offering leveling functionality and a surrounding protection plate.

References
1 Jou, J.M., Lewis, S.M., Briggs, C., et al. ICSH review of the measurement of the erythrocyte aedimentation rate. Int. J. Lab Haemat., 2011: 33, 125-132
2 Clinical and Laboratory Standards Institute (CLSI). Procedures for the Erythrocyte Sedimentation Rate Test. Approved Standard, Fifth Edition H02-A5, May 2011. ISBN 1562387545