The sensitive and highly specific quantification of biomarkers or other target proteins is done with isotopic dilution and LCMS analyses. This is especially important for 

  • determination of absolute protein amounts
  • when available antibodies exhibit unspecific binding

Feasibility

A proteolytic digest of the sample material in question will be analysed to find suitable proteotypic peptides. Isotopically labelled synthetic mimics of these peptides are obtained for use as internal standards. 

Method development