title: Immunoreactive insulin in diabetes mellitus patient sera detected by ultrasensitive ELISA with thio-NAD cycling.
abstract: To minimize patient suffering, the smallest possible volume of blood should be collected for diagnosis and disease monitoring. When estimating insulin secretion capacity and resistance to insulin in diabetes mellitus (DM), increasing insulin assay immunosensitivity would reduce the blood sample volume required for testing. Here we present an ultrasensitive ELISA coupled with thio-NAD cycling to measure immunoreactive insulin in blood serum. Only 5 μL of serum was required for testing, with a limit of detection (LOD) for the assay of 10(-16) moles/assay. Additional recovery tests confirmed this method can detect insulin in sera. Comparisons between a commercially available immunoreactive insulin kit and our ultrasensitive ELISA using the same commercially available reference demonstrated good data correlation, providing further evidence of assay accuracy. Together, these results demonstrate our ultrasensitive ELISA could be a powerful tool in the diagnosis and treatment of not only DM but also many other diseases in the future.
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Ito
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan.
authors.forename: Mugiho
authors.initials: M
authors.lastname: Kaneda
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kodama
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan.|R&D Headquarters, TAUNS Laboratories, Inc., Izunokuni, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Morikawa
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan.
authors.forename: Momoko
authors.initials: M
authors.lastname: Tai
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Aoki
authors.affiliation: R&D Department, BL Co. Ltd., Izunokuni, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Watabe
authors.affiliation: R&D Headquarters, TAUNS Laboratories, Inc., Izunokuni, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Nakaishi
authors.affiliation: Institute for Health Sciences, Tokushima Bunri University, Tokushima, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Hashida
authors.affiliation: Faculty of Medicine, Kagawa University, Miki, Japan.|Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Takamatsu, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tada
authors.affiliation: Faculty of Medicine, Kagawa University, Miki, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kuroda
authors.affiliation: Faculty of Medicine, Kagawa University, Miki, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Imachi
authors.affiliation: Faculty of Medicine, Kagawa University, Miki, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Murao
authors.affiliation: Faculty of Science, Hokkaido University, Sapporo, Japan.
authors.forename: Masakane
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan.
authors.forename: Teruki
authors.initials: T
authors.lastname: Yoshimura
authors.affiliation: Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miura
mesh_terms: D003920:Diabetes Mellitus / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000276:immunology; D057230:Limit of Detection; D009243:NAD / Q000031:analogs & derivatives / Q000737:chemistry; D012680:Sensitivity and Specificity
chemical_list: D007328:Insulin; D009243:NAD; C003451:thionicotinamide adenine dinucleotide
keywords: ELISA; diabetes mellitus; enzyme cycling; insulin; thio-NAD cycling