This BIOPHEN™ ANTI-Xa (2 Stages heparin Assay) kit is a two-stage chromogenic assay for measuring the activity of heparins (UFH or LMWH), in manual or automatic method. This method is proposed only to test heparin in human citrated plasma, or in purified solution. This kit is for research use only and must not be used from patient diagnosis or treatment. NOTE: This product replaces Ref #221010 and requires separate purchase of specific buffers depending on the analyte being tested and compendia reference desired: Specific buffer needed for UFH Assay, USP or EP: AR030K Specific buffers needed for LMWH Assay, USP: AR005L, AR029K, AR028K Specific buffers for LMWH Assay, EP: AR005L, AR029K