CitrISO for in-vitro diagnostics


Both, trisodium citrate as well as tri-arginine citrate, are applicable to adjust the BE of an anticoagulant to 0 mmol/l. Therefore the solution has no influence on the blood pH or BE, respectively.

The high sodium burden when trisodium citrate is used is not critical for in-vitro application. Even with trisodium citrate it is possible to produce an isotonic solution. However the concentration has to be 109 mmol/l.

Consequently one crucial condition for coagulation diagnostics is met: For true coagulation diagnostics it is essential that the initial in-vivo pH of the sample remains unchanged to observe all acidosis and alkalosis caused coagulation disorders. This in-vivo (ex-vivo) diagnostics is performed ideally at the point of care (POC).

CitrISO example

For in-vitro application (e.g. coagulation diagnostics) a solution composed of the following is useful:

24.0 mmol/l sodium hydrogen carbonate
01.5 mmol/l tripotassium citrate
39.0 mmol/l trisodium citrate
56.7 mmol/l tri-arginine citrate

This isotonic solution with a total citrate concentration of 97.2 mmol/l has an osmolality of 293 mosmol/kg H2O and a pH (37 °C) of 7.25. The solution is isokalemic (potassium 4.5 mmol/l), isonatremic (sodium 141 mmol/l) and isohydric (BE = 0 mmol/l).

Sources of supply and scientific argumentation

The raw material tri-arginine citrate, stock solutions for further processing, custom-made specifications and solutions ready to use (IVD) are available at
Bioanalytic GmbH (,

Scientific arguments for CitrISO can be found on the information portal Physioklin ( > PhysioHäm).

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