in case of problems is Mikhail Ovanesov (who can be reached at mikhail.ovanesov@fda.hhs.gov). Requests can be made via email at CBERShippingRequests@fda.hhs.govStandard for potency measurements of thrombin concentrates, calibrated in IU and US ("NIH") units. US customers order from FDA/CBER.A project to replace this standard is underway and until this is complete we are restricting orders to a maximum of 4 ampoules per order and 2 orders per year at most, without prior discussion