Key Features

A fusion reagent used to transfer water-soluble proteins into the cytoplasm of living cells

  • The lumen of fusogenic liposomes is used as a carrier for water-soluble proteins
  • Superior fusion efficiency (up to 80-100%)
  • Fusion process completed within 1 – 20 minutes
  • Optimized for the transfer of low and intermediate protein amounts to prevent concentration-induced artifacts in cell behavior
  • Lyophilized

in cooperation with


Special Requirements?



  • Transfer of labeled proteins or peptides into living cells for functional imaging, speckle analysis, FRAP, or single molecule analysis, etc.
  • Incorporation of antibodies or blocking antibodies into living cells
  • Blocking, induction, or replacement of protein-induced/regulated signal cascades
  • Re-incorporation of proteins into mutant cells

Transferred proteins are instantly active inside the cells, and after membrane fusion, cells can immediately be used for further analysis. Since proteins are freed directly into the cytoplasm, no partial or complete lysosomal degradation can occur, as is typical for other endosomal uptake-depending proteofection methods. Depending on your experimental needs, the fusion process can be monitored by fluorescence microscopy.


Form Lyophilized powder
Storage -20 °C
ExMax/EmMax 750/780 nm (infrared)

: Transfer of heavily charged proteins can affect fusion efficiency.

Glycerol (>5 %) and BSA will obstruct the transport of peptides/proteins.

Fuse-It-P vesicles were filled with LifeAct and fused with myofibroblasts. A bright staining of the actin cytoskeleton can be observed after 5 minutes.

For details please watch the according videos:

Individual Staining


Principle of Membrane Fusion

The incorporation of small liposomal carriers into the plasma membrane of mammalian cells is the idea behind all of ibidi’s Fuse-It products. Liposomal carriers are able to attach and instantly fuse with plasma membranes in a physicochemical-driven manner. ibidi’s new Fuse-It reagents efficiently use this mechanism and fuse with mammalian cell surfaces immediately upon contact. Therefore, this novel technique makes the transfer of molecules independent of biological processes, such as endocytosis, pinocytosis, or specific receptor binding.

Additional information

Pack Size

100 µl, 4 x 25 µl, 400 µl, 4 x 100 µl