Validate Anti-Xa for Heparin Therapeutic Range?

If I wanted to perform an anti-Xa assay to determine my therapeutic range for my new lot of partial thromboplastin time (PTT) reagent, does the Xa need to be a validated test on my analyzer?

Hello, and yes, the reference method must be validated to insure the PTT therapeutic range is valid. If you aren’t able to validate locally, most reference laboratories will perform a validated anti-Xa using your patient aliquots. Because labs need the chromogenic anti-Xa heparin assay to set the PTT therapeutic range, it makes sense to many directors to simply use the anti-Xa itself, which also enables the laboratory to measure low molecular weight heparin and the synthetic pentasaccharide fondaparinux.