Certain features of will be down for maintenance Saturday afternoon/evening, February 24th starting at 3:00 pm CT until 9:00 pm CT.

Please note that you still have telephone and email access to our local offices. We apologize for any inconvenience.

SILu™tions – Stable Isotope-labeled MS Internal Standards

What happens when you combine state-of-the-art technology with scientific prowess? Full-length protein standards with the highest purity and isotopic incorporation in the industry. Stable isotope-labeled (SIL) internal standards and high quality calibrations are the essential tools to precisely measure target protein quantitation in mass spectrometry proteomic assays. Our innovative SILutions portfolio meets the needs of different protein quantitation approaches. It’s innovation delivered to you – just right, right now.

For more tools to complete your workflow, visit

SILuProt (full-length proteins)
• Best MS proteomic internal standards
• Injected into sample before enzymatic
• Cover major human biomarkers
• Unlabeled versions available for use as
  calibrators (SILu™Lite)

• Full-length antibody protein standard
• Highly purified stable isotope-labeled
  universal IgG monoclonal antibody
• Critical tool for pharmacokinetic
  properties of biotherapeutics
• Unlabeled SigmaMAb available for MS
SILuPrEST (50-150 aa)
• Intermediate in length between
  SILuProt and AQUA
• Substantial proteome coverage
• Injected into sample before or after
  enzymatic digestion
• Multiple tryptic peptides per SILuPrEST

AQUA (≤30 aa)
• Accurately quantitate low abundance
• Measure site-specific phosphorylation
• Injected into sample after enzymatic
• Custom synthesis available