Abstract: A disposable element is provided for use in analytical equipment for electrochemical determination of biological cells. The disposable element comprises a working electrode, a reference electrode, and a filter for retention of solids in the vicinity of the electrodes. The analytical equipment with disposable elements can be used for respiratory assays, enzyme assays or immunoassays, among other uses.In a variation, the disposable element comprises a reference electrode, working electrode and fusible link.

Abstract: A method for the assay of haemoglobin in blood is provided in which the blood is contacted with a sufficient amount of a ferricyanide and the haemoglobin is electrochemically assayed by monitoring the current changes produced on reduction of the ferricyanide by the haemoglobin.

Abstract: The invention disclosed relates to an electrochemical assay which is particularly concerned with an assay for the presence of, or amount of, glycosylated haemoglobin in a blood sample, but which extends to a general assay for detecting the presence of, monitoring the level of or determining the concentration of compounds containing cis-diol groups, such as glycols, nucleic acid components, sugars, polyols, catechols and glycosylated proteins.When ferrocene boronic acid or a derivative thereof is present free in solution, it can act as a mediator for a wide range of oxido-reductases. However in the presence of, for example, sugars containing the cis-diol structure, the metallocene (such as ferrocene boronic acid) covalently binds to the sugar. When the ferrocene boronic acid is thus bound, it is essentially immobilized and its properties as a mediator and ability to diffuse will be markedly affected.

Abstract: The specification discloses a method and apparatus for the assay of salicylate (or a derivative thereof) comprising a conducting body having at a surface thereof an enzyme capable of catalyzing the conversion of salicylate (or a derivative thereof) to a catechol whereby said catechol is subject to direct electrochemical measurement as it oxidizes at said surface to generate a current as a measure of the reaction taking place and thereby of the concentration of salicylate at said surface. The method typically comprises the steps of;(a) treating a liquid sample suspected of containing salicylate or a derivative thereof with an enzyme capable of catalyzing the conversion of salicylate or a derivative thereof into a catechol, and,(b) measuring the concentration of catechol in the treated sample by direct electrochemistry.