Human proinsulin elisa kit

IAPP levels were determined in plasma with a human IAPP ELISA kit (Linco, Research, Inc. St Charles, Mo., USA), plasma proinsulin levels with a human proinsulin ELISA kit (Mercodia, Uppsala, Sweden) and glucagon concentration with a human glucagon radio immuno assay (Linco). C-peptide was measured in serum samples with a time-resolved fluoroimmunoassay (AutoDELFIA™ C-peptide kit, Wallac, Turku, Finland) as the study progressed. The detection level was 0.03 nmol/L. Each assay was validated by inclusion of a C-peptide control module containing a high, a medium and a low-level control (Immulite, DPC, UK). A 1224 MultiCalc progra (Wallac) was used for automatic measurement and results calculation. All samples were analysed in duplicates at Linköping University. IAA measurements in plasma were performed with radiobinding assay at Lund University.

The SC-β cell clusters were lysed overnight in acidified alcohol at −20 °C after 2 h starvation in 2 mM glucose Krebs-Ringer buffer. The supernatants were used to measure proinsulin and C-peptide levels using a human proinsulin ELISA kit (Mercodia, #1118-1-10) and a human ultrasensitive C-peptide ELISA kit (Mercodia, #0111-1-10).