US Patent 7374943 Haemoglobin assay

The invention provides a kit for a glycated haemoglobin assay, said kit comprising: a porous membrane capable of retaining precipitated haemoglobin; a first reagent comprising zinc ions in aqueous basic solution or comprising a water soluble zinc compound; a second reagent comprising a chromophore-boronic acid conjugate; and optionally, an aqueous washing reagent; wherein at least one of the first and second reagents further comprises a surfactant capable of lysing erythrocytes, and wherein said second reagent if liquid is acidic.