HPLC analysis of HbA1c in dried blood spot samples (DBS): a reliable future for diabetes monitoring.

To simplify collection and transport of blood for HbA1c measuring, we have studied the use of a special paper that absorbs a defined volume of capillary blood and quickly dries it (dried blood-spot, DBS). The DBS can be sent to a central laboratory using regular postal service and without temperature control. This system differs greatly from other proposed DBS methods for HbA1c because it overcomes the haemoglobin alterations during the drying and storing processes, that otherwise make this analysis unreliable.

"Method-specific" stability of serum C-peptide in a multicenter clinical study.

A Central laboratory that participates in multicenter clinical studies must consider and study the parameters that condition the in vitro stability of the analytes. We evaluated the effect of temperature on serum C-peptide storage during transport from clinical research centers to the Central laboratory. In particular, the stability for storage lengths from 0 to 24-48 hours at temperatures of between -20 degrees C and +37 degrees C were studied: the C-peptide assay was performed by means of a chemiluminescence and a RIA method.