A reaction cassette for a glycated hemoglobin meter is provided, the reaction cassette comprising a first storage holder for sealingly storing a first reagent by a foil cover, a reaction zone for providing a space for reacting a blood sample with the first reagent, and a measurement zone for providing a space for measuring an amount of glycated hemoglobin in the blood sample, wherein the reaction cassette further comprises a locking jaw configured to form an opening in the foil cover, wherein the first reagent flows from the first storage holder toward the reaction zone via the opening formed in the foil cover, wherein a mixture is obtained by reacting the blood sample with the first reagent in the reaction zone.