ChromoTek launches RFP-Trap and GFP-Booster bioimaging reagents
2 April 2010
German company ChromoTek has launched two new bioimaging
reagents, RFP-Trap and GFP-Booster.
RFP-Trap is used to identify and pull down interaction partners of
proteins tagged with RFP (red fluorescent protein) and GFP-Booster
restores or increases the GFP (green fluorescent protein) signal in
RFP-Trap is a versatile tool for biochemical and cell biological
analysis of RFP-tagged fusion proteins in pull-down assays (a
frequently used in vitro method used to determine physical
interaction between two or more proteins).
Generally, pull-down experiments have been performed with
antibodies, but as they are bulky molecules they tend to
disintegrate during the purification process, making it difficult to
further analyze the proteins of interest by mass spectrometry or the
Western blot method.
ChromoTek has found a way to circumvent this problem by using
small recombinant binding molecules, so called nanotraps instead of
antibodies. Nanotraps bind their targets with similar efficiency but
are only a tenth of the size of conventional antibodies and much
more stable, thus allowing to effectively reduce background in pull
The RFP-Trap pulls down all major
of RFP (mCherry, mOrange) from cell
with minimal background
GFP is a powerful tool to study protein localization and dynamics
in living cells. However, the photo stability and the quantum
efficiency of GFP are not sufficient for super-resolution microscopy
(e.g. 3D-SIM or STED) of fixed samples from cells expressing GFP
fusion proteins to visualize specific structures. Furthermore, many
currently used procedures for FISH or BrdU detection lead to
disruption of the GFP signal. ChromoTek now has developed a GFP
booster consisting of a chemical fluorescent dye that is covalently
attached to a GFP Nanotrap thus providing high fluorescence
intensities and signal-to-noise ratios.
Figure 2. Enhancement of GFP signal with
GFP-Booster after EdU-Click-iT treatment. EdU-Click-iT™ treament
leads to disruption of GFP signal. GFP-Booster labels GFP fusion
proteins and thus reactivates and boosts the fluorescence.
Fluorescent proteins are indispensible markers that have enabled
scientists to visualize molecular interactions within cells. The two
most popular markers, GFP and RFP, are used in thousands of labs
worldwide as tags for cellular proteins. GFP has proved to be so
important for modern biomedical research that it earned the 2008
Nobel prize for its discoverers Osamu Shimomura, Martin Chalfie and
Roger Y Tsien.