Validity and use of a non-parallel insulin assay for pharmacokinetic studies of the rapid-acting insulin analogue, insulin aspart

J Immunoassay Immunochem. 2001;22(2):147-63. doi: 10.1081/IAS-100103226.


A radioimmunoassay (RIA) for insulin was validated for reliable measurement of the human insulin analogue, insulin aspart, by correction of non-linear measurements. Specificity was equivalent for several species of insulin, except insulin aspart. A non-linear hyperbolic model fitted insulin aspart with a correction formula for non-linearity of: z = 1,503y/ (1,398 - y), where y denotes measured concentration and z denotes true concentration. Matrix-effects were insignificant for human, porcine, and canine heparin-plasma and for human and porcine serum. The coefficient of variation was below 15% for 80-800 pmol/L human and porcine insulin and for 80-600 pmol/L insulin aspart. The limit of detection for insulin aspart was 11.5 pmol/L with a lower limit of quantification of 17.5 pmol/ L. Dilution of serum with Pharmacia dilution media introduced no significant error. In conclusion, this paper demonstrates that a non-parallel radioimmunoassay can be used to estimate accurate concentrations of insulin aspart.

Publication types

  • Validation Study

MeSH terms

  • Animals
  • Dogs
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Insulin / analogs & derivatives*
  • Insulin / pharmacokinetics*
  • Insulin Aspart
  • Radioimmunoassay
  • Sensitivity and Specificity
  • Swine


  • Insulin
  • Insulin Aspart