Does anyone offer methotrexate by HPLC or tandem mass spec? We have a patient who has been given carboxypeptidase G2 rescue therapy. Our method (ARKTM Methotrexate on Dimension EXL) crossreacts with
the minor metabolite DAMPA and the manufacturer states that the assay should NOT be used for patients on carboxypeptidase G2 therapy.
Please could you also let me know sample requirements?
With many thanks,
Dr Agatha van der Klaauw, PhD
SpR Chemical Pathology/ Metabolic Medicine
Department of Clinical Biochemistry
Addenbrooke's Hospital
Cambridge