Fluorescent Proteins
The intricate and complex dynamics within a cell and in a cell population can be captured in real time using fluorescent proteins (FP). Fluorescent proteins (e.g., EGFP) have become well established marker for gene expression and protein targeting in intact cells and organisms. This temporal and spatial resolution helps in detailed understanding of various pathways and events related to biochemical functioning in living cells. Almost all endogenous proteins of interest can be fused to FPs and its variants and this has numerous applications in life sciences that include protein interaction, FP tagging of specific proteins and their trafficking within cells, following fate of specific protein populations within a cell, paracrine interactions, and in-depth understanding of signal transduction pathways in real-time.
BioVision offers the brightest Green / Red / Blue / Cyan / Yellow / mCherry fluorescence proteins that expressed from E. Coli. These recombinant proteins were purified using a proprietary technology that ensures highest purity and fluorescence intensity. Green Fluorescent Protein (GFP) was one of the first discovered proteins from the jellyfish Aequorea victoria. Upon purification of this GFP it was found to fluoresce on its own without requiring any coenzymes and substrates. The GFP gene thereby contained all the necessary transcriptional elements needed for the synthesis of the fluorophore. In recent years there has been an explosion in the availability of a large variety of FPs thus providing a wide array of tools for simultaneous tagging of various proteins within the same cell. These include red FP (mCherry and dsRED), yellow FP (YFP), cyan FP (CFP), blue FP (BFP) and a wide range of other colors and options. The availability of a wide spectrum of FP's entails that the researcher use the best possible combination of FP's that will result in minimal wavelength cross reactivity between their excitation and emission spectrum (Fig.1). Multiple labeling of a number of proteins in the same cell, with different fluorescent proteins enables to study the active colorful dynamics within a single cell. Table 1 represents a set of FP's that can be used for multiple labeling studies with a simple optical set up. These proteins can be used in a number of fluorescent imaging studies and generally have the following characteristics:
a. They are not toxic in the system under study, are expressed very efficiently and are significantly bright at levels higher than the autofluorescence
b. The FPs do not oligomerize upon co-expression
c. They are photostable for extended times and suitable temperatures
Fluorescence proteins are also very useful in gene expression and many other applications including: use as standards for SDS-PAGE, Western blot analysis, fluorometer and flow cytometer calibration, fluorescence microscopy, and microinjection into cells and tissues, etc. Antibodies against these proteins and mammalian expression vectors, as well as GFP quantification kit area also available.
