Please note that the IBEX definition of units differs from the Sigma definition.
IBEX enzymes are sold in “International Units”. For heparinase this means that one international unit (IU) is defined as the amount of enzyme that will liberate 1.0 µmole unsaturated oligosaccharides from heparin or heparan sulfate per minute (at 30 °C and pH 7.5).
Sigma Units are defined as follows:
One unit (Sigma unit) will form 0.1 μmole of unsaturated uronic acid per hour at pH 7.5 at 25 °C.
Therefore one IBEX unit (IU) is equivalent to approx. 600 Sigma units.
All IBEX products [except Collagen ELISA kits and Collagen Antibodies] are manufactured under the ISO certified system, ISO 13485.