Improved sample collection technique for capillary blood on filter paper for determination of glycated haemoglobin.

A simple and practical method of sampling capillary blood was tested. This method was used for determination of glycated haemoglobin by ion exchange chromatography. Capillary blood was collected onto filter paper and placed in a small polypropylene tube containing phosphate-buffered sodium chloride with EDTA and p-hydroxybenzoic acid methyl ester. There was good correlation between filter paper sampling and conventional sampling in tubes with EDTA as anticoagulant. With this new sampling technique the glycated haemoglobin value was stable for 7 days at room temperature and for at least 10 days at +4 degrees C. Sampling can be performed by the patient at home and the sample then mailed to the laboratory, thus enabling analysis to be performed prior to the patient's visit to the physician.