Autoantibodies to pancreatic beta cell antigens are important serological markers of type 1 diabetes mellitus (type 1 DM). The antigens recognised by these antibodies include insulin, glutamic acid decarboxylase (GAD65 kDa isoform), the islet cell antigen named IA-2 or ICA-512 and zinc transporter 8 (ZnT8). 3 Screen ELISA allows simultaneous measurement of GAD, IA-2 and ZnT8 autoantibodies in the same sample.