We are experiencing problems with our automated ASPEC/HPLC normet assay re:stability of calibrators/QC, poor reproducibility and calibrators routinely failing the pH check. Does anyone else use this method and seem to be suffering similar problems? Fiona Ivison Dept of Clinical Biochemistry Manchester Royal Infirmary Oxford Road Manchester M13 9WL 0161 276 4062 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%