Drug Discovery

Instruments, software and methods for the analysis of molecular interactions.

LigandTracer® measures protein interactions, minute by minute, during incubation and after wash. The binding curve displays the amount of bound protein over time, and contains information about affinity, kinetics and complexity.The software running all LigandTracer models is designed to facilitate measurement startup and improve understanding of your real-time data. Together with thorough support material, you master the instruments in a few days.There are currently four different instrument types available. Choose model depending on your label:

  • LigandTracer Green
    Fluorescence: Blue/Green, Yellow/Red or Red/NIR
  • LigandTracer Grey
    Low energy gamma, such as 125I
  • LigandTracer Yellow
    High energy gamma, including 177Lu, 111In, 99mTc, 18F and 11C
  • LigandTracer White
    Beta, e.g. peptides pre-labeled with 14C or 35S

All our instruments are delivered with a computer, LigandTracer control software and the evaluation software TraceDrawer.

Technology of LigandTracer is based on repeated differential measurements of surface associated proteins. Cells are seeded in a local part of a cell dish and the opposite side is used as a reference. The dish is placed on an inclined, slowly rotating support and liquid containing labeled protein is added. The detector, which is mounted over the upper part, registers the additional activity of proteins bound to the cells. Each revolution results in a peak, which is an accurate measurement of the amount of bound protein. The peak height is followed over time, providing an accurate estimation of the kinetics of the interaction.Main benefits of LigandTracer compared to manual measurements: 

  • Protein-cell interactions can be followed in real-time during minutes, hours, or days
  • Binders with rapid dissociation rates can be correctly characterized
  • Washing steps are not needed
  • Counting cells are not needed
  • LigandTracer saves reagents and labor time


Green is made for the regular cell-biology and opens up completely new possibilities in binding assays. By introducing time into the assay, more information is extracted and results become more robust.Key features:

  • Detect protein-cell interactions in real-time, both during incubation and after wash
  • Simple, portable, affordable
  • Use less disposables
  • Save labor time
  • Interchangeable detector

Detector availability:

  • Blue (488nm) – Green (535nm)
    For FITC and similar fluorophores
  • Yellow (590nm) – Red (632nm)
    For Rhodamine Red and similar fluorophores
  • Red (632nm) – NIR (670nm)
    For Alexa Fluor® 633 and similar fluorophores


LigandTracer Grey is the workhorse in laboratories using 125I-labeled proteins. With repeatability better than most other cell-based assays and versatility through open design, cell-based binding assays have a new yardstick.Key features:

  • Detect protein-cell interactions in real-time, using 125I-labeled proteins
  • Simple, portable, affordable
  • Use less disposables
  • Save labor time
  • Run in incubator/cold room

LigandTracer Yellow is designed to speed up the development of medical imaging agents. Equipped with a scintillator-based detector suitable for all nuclides used in PET/SPECT imaging, real time binding assays is made possible, even for short-lived nuclides like 11C. 

Key features:

  • Detect protein-cell interactions in real-time, using proteins or PET/SPECT tracers
  • Simple, portable, affordable
  • Use less disposables
  • Save labor time
  • Run in incubator/cold room