Dilution principle

The principle of adding Diluent to a flow of whole blood is unique. The Interrliner has the capability of monitoring the air displacement during the aspiration cycle. This is called on-line dilution. The CPU receives data from the airflow sensor and calculates the syringe speed. Diluter accuracy is ± 3%.

The citrate dilution (4:1) takes place to reduce the influence of HCt (Hematocrit) on the sedimentation process. Dilution brings the Hct level from 0.45 (considered as a normal level) to 0.36. The ICSH (1993) recommended the use of EDTA samples with a Hct of 0.35 or less. Dilution errors up to 25% results in a 5% variation in Hct of the prepared sample. This is within the natural variation in Hct between individual humans and will not have significant influence on the accuracy of the ESR measurement.