Quantitative assessment of collagenase blends for human islet isolation.

Background: The variability in collagenase blends has been speculated as the single most important determinant of the success or failure in isolated islet yields in clinical islet transplantation. Examination of the formulation and potency of the widely used Liberase HI enzyme blend will uncover possible sources of imprecision.

Methods: High performance liquid chromatography (HPLC) and kinetic measurements of collagenase and protease activity were used to assess potency.

The EMIT 2000 tacrolimus assay: an application protocol for the Beckman Synchron LX20 PRO analyzer.

Objective: To develop and evaluate the performance of an application protocol for the EMIT 2000 tacrolimus (Tac) assay on the Beckman Synchron LX20 PRO Analyzer.

Design And Methods: Precision, accuracy, linearity, and lower limit of quantitation were investigated. Specimens from 212 kidney, liver, heart/heart-lung, and islet cell transplant patients were analyzed and results were compared to those from the Abbott MEIA II assay.