The application of Biosystems

Dr Manfred Rauh, head of the clinical laboratory, explained why this instrument was chosen: ôMany of our research programmes are looking at the potential of new technologies to investigate various metabolic parameters, including amino acids, peptides and steroids, from all kinds of samples û plasma, urine, saliva and dried blood spots. These projects focus mainly on metabolic disorders and therapeutic drug monitoring of, for example, immunosuppressive drugs in children following bone marrow transplantation. The low concentrations of many metabolites and steroids in children and the small sample volumes we receive require specific analytical methods and the API 4000 offers excellent sensitivity in these cases, particularly for steroid analysis. We are very pleased with the instrument as it is extremely reliable and results are not affected by matrix effects, unlike with immunoassays. Also, we can analyse different substances simultaneously, which is important because drugs are now often used in combination and there are many interferences and interactions between them that must be considered. Another of our interests is the development of a method that uses the assessment of saliva as a diagnostic fluid, say for therapeutic drug monitoring. Saliva would be a welcome option in paediatrics as it is non-invasive and avoids the use of needles for sick children, and the LC/MS/MS method copes well with this kind of sample.ö