Does anyone use SST tubes for primary tube sampling on their routine biochemistry analyser? We do and have been having lots of problems with the gel getting into the lines and ending up in the flow cell of our Beckman CX7 analysers. It gets a bit serious when it happens twice in one week. The problem is compounded by a high number of ICU and renal patients on anticoagulant therapy whose specimens from time to time form fibrin clots even after a 10 minute centrifugation. If this sounds familiar to anyone, I'd like to hear from you. Thanks, Una Gibbons P.O.Box 1331, Seeb C.P.O. 111 Sultanate of Oman [log in to unmask] Tel/Fax: 968 593221 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%