A new device to improve the accuracy of blood glucose measurements with glucose-oxidase reagent strips is described. The device ensures that an adequate amount of blood is applied onto the reagent pad when the strip is fully inserted. When the strip is withdrawn, the pad is automatically wiped, and so the reaction can be accurately timed. The device also reduces the risk of blood contamination of other surfaces. Use of a prototype of this device enabled more accurate measurement of blood glucose on general wards.