Protein Expression & Imaging

The World of Fluorescent Proteins

A comprehensive guide to fluorescent markers, their spectral properties, and the highly specific antibodies used to detect them across applications.

Fluorescent proteins have revolutionized molecular and cellular biology, providing incredibly powerful tools for visualizing and understanding dynamic biological processes in real time.

Derived originally from naturally occurring proteins found in marine organisms, these fluorescent markers allow scientists to tag and track proteins, cells, and entire tissue lineages with remarkable precision. The discovery of the green fluorescent protein (GFP) from the jellyfish Aequorea victoria paved the way for the development of a vast array of colored fluorescent proteins through advanced genetic engineering.

While intrinsic fluorescence is useful for live imaging, highly specific antibodies against these proteins enable researchers to precisely detect, quantify, and analyze these markers in fixed tissues, cell lysates, and flow cytometry.

1. Fluorescent Protein Spectral Guide

Understanding the excitation and emission spectra of your chosen tag is critical for avoiding spectral overlap in multi-color experiments. Below is a comprehensive reference guide linking to our specific detection reagents.

Protein Name	Excitation (nm)	Emission (nm)	Visual Color
EBFP	380	440
ECFP	433	475
EGFP	488	509
mBanana	540	553
mOrange	548	562
tdTomato	554	581
mTangerine	568	585
mStrawberry	574	586
mCherry	587	610
mGrape1	595	620
mRaspberry	596	625
mPlum	590	648

2. The Foundational Fluorescent Proteins

GFP, YFP, and RFP are the cornerstone tools in fluorescent imaging. These proteins remain fundamental for visualizing and studying cellular and molecular processes globally. While intrinsic fluorescence is useful for live-cell tracking, researchers universally rely on specific antibodies against these proteins for comprehensive downstream assays.

GFP

GFP (Green Fluorescent Protein)

GFP natively fluoresces green and has been extensively modified to improve its brightness and stability, resulting in variants like eGFP. Anti-GFP antibodies are perhaps the most heavily utilized tag antibodies in modern biology.

YFP

YFP (Yellow Fluorescent Protein)

A derivative of GFP, YFP emits yellow fluorescence and is particularly useful in multi-color labeling experiments and highly sensitive FRET (Förster Resonance Energy Transfer) assays.

RFP

RFP (Red Fluorescent Protein)

With its far-red emission, RFP is ideal for deep-tissue imaging, minimizing background autofluorescence, and reducing cellular phototoxicity.

3. tdTomato: The Bright Red Beacon

tdTomato is a standout red fluorescent protein known for its unparalleled brightness and photostability. Derived from a mutant of the Discosoma sp. red fluorescent protein (DsRed), tdTomato matures incredibly quickly, making it ideal for live-cell imaging and long-term developmental studies.

The tandem dimer contains two copies of dTomato linked by a 12-amino acid linker. Due to its pair of chromophores, tdTomato is extremely bright and exhibits unique light stability. The biggest disadvantage of tdTomato is that it is a large molecule and may interfere with the folding of fusion proteins in some cases.

Primary Antibody Applications

Researchers frequently use Biorbyt’s tdTomato Antibody (orb182397) for comprehensive downstream validation:

• Western Blotting: Detects tdTomato-tagged proteins, definitively verifying their expression levels in cell or tissue lysates.
• Immunohistochemistry (IHC): Visualizes expression in fixed tissues or transgenic mouse models (where native fluorescence is lost during fixation), providing spatial context.
• Immunoprecipitation (IP): Enriches and isolates tdTomato-tagged proteins from complex mixtures to study protein-protein interactions.

4. mCherry & mOrange Spotlights

mCherry: The Versatile Red Marker

mCherry is another incredibly popular red fluorescent protein derived from DsRed. It is strictly monomeric, making it highly suitable for direct fusion with other proteins without disrupting their native structural function. Its robustness and versatility have made it a go-to marker for studying protein-protein interactions and monitoring cellular events.

View highly validated anti-mCherry Antibody →

mOrange: The Bright Orange Option

mOrange offers bright orange fluorescence, making its distinct color profile highly valuable for multi-color labeling experiments. This allows researchers to visualize multiple cellular components simultaneously without spectral bleed-through. mOrange's brightness and stability have made it a favorite in studies requiring precise and clear imaging.

View anti-mOrange Monoclonal Antibody →

5. mScarlet & Other Engineered Variants

mScarlet is a newer addition to the family of red fluorescent proteins, engineered for exceptional brightness and maturation speed. Its high quantum yield and incredible photostability make it an excellent choice for super-resolution microscopy and other advanced imaging techniques. We provide robust mScarlet antibodies to confirm expression and conduct Co-IP interaction studies.

Browse Other Specialized Tags

Biorbyt offers a wide range of high-quality antibodies targeting both classical and highly specialized fluorescent variants.

Fluorescent Marker CFP Antibody Detect Cyan Fluorescent Protein expression reliably across Western Blot and IF applications. Fluorescent Marker Venus Antibody Highly specific antibody against Venus, an exceptionally bright variant of YFP used heavily in FRET. Fluorescent Marker mRuby Antibody Validate the expression of mRuby, a bright, monomeric red fluorescent protein. Fluorescent Marker mStrawberry Antibody Monoclonal antibody targeting the mStrawberry variant for robust protein detection. Fluorescent Marker mPlum Antibody Detect mPlum, a far-red fluorescent protein highly suited for deep tissue imaging. Fluorescent Marker mBanana Antibody Specifically target and validate the expression of the mBanana fluorescent variant.