Cy3B NHS Ester is an improved version of Cy3, a bright, water-soluble and pH-insensitive orange fluorescent dye from pH 4 to pH 10. Cy3B conjugates of antibodies, peptides, and proteins can be excited using the 532 nm or 555 nm laser line and visualized using the TRITC (tetramethylrhodamine) filter set. Compared to TAMRA and most other commonly used fluorochromes, Cy3 conjugates generate less background and provide improved fluorescence quantum yield and photostability.
NHS esters (or succinimidyl esters) are the most commonly used amine-reactive groups for labeling proteins with primary amines (Lys), amine-modified oligonucleotides, and other amine-containing molecules. The Cy3 NHS ester is not recommended for labeling high molar ratio proteins due to its significant self-quenching properties and is only recommended for detection of medium to high abundance targets. For detection of low-abundance biological targets, we recommend APDye 555 NHS Ester (Alexa Fluor ® 555 analog), which can be attached to proteins at high molar ratios without significant self-quenching, allowing for brighter coupling Conjugates and more sensitive detection
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.