Has anyone found a QC material to use with the K-check tablet? we are currently using urine controls but the bulk of our ketone testing is on serum. Bio-Rad makes one for use on some chemistry analyzer but when I talked to them about it they said it was unsuitable for the K-check tablet stating that it made a speckled pattern on the tablet rather than the solid purple a positive patient would leave. JCAHO seems to be concerned about "matrix" as we found out 20 years ago when we were only using urine controls for pregnancy kit tests. Thanks