ARS | Publication request: Rapid colorimetric microplate assay for determining glucose and sucrose content in potato tubers

Submitted to: Potato Association of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 27, 2007
Publication Date: August 12, 2007
Citation: Bethke, P.C., Busse, J.S. 2007. Rapid colorimetric microplate assay for determining glucose and sucrose content in potato tubers [abstract]. Potato Association of America Proceedings 91st meeting. Paper No. 06A.

Technical Abstract: Accurate quantification of tuber glucose and sucrose content is important for scientific as well as commercial purposes. High pressure liquid chromatography (HPLC) and enzyme coupled assays are accepted methods for determining sugar concentrations. HPLC assays require expensive equipment and lengthy sample preparation times. Because of this, HPLC is rarely used for routine monitoring of tuber sugars. Sample preparation times for enzyme-based assays are much shorter than for traditional HPLC methods, and this makes them attractive management tools for routine sugar monitoring. We have developed a reliable, cost-effective 96 well microplate enzymatic assay that allows us to determine quickly sugar concentrations in tuber samples. Samples can be prepared from fresh, frozen or freeze dried material, and sample size can be as little as 1g of fresh material. This colorometric assay utilizes coupled reactions of glucose oxidase and peroxidase to accurately measure glucose concentrations as low as 10 µM. Sucrose content can be determined at the same time by adding invertase, an additional enzyme mediated step. Data from this improved enzymatic assay compare favorably with HPLC data, with the added benefits of lower capital outlay and faster sample turn around times. (Oral, Physiology, PAA membership 748)