Quantum dots (QDs) are fluorescent semiconductor nanocrystals that have unique optical and electronic properties including size tunable emission wavelength, superior brightness, high resistance to photobleaching, and simultaneous excitation of multiple colors from a single light source. They offer high photostability and high fluorescence with great long-term colloidal stability over a broad pH range. The surface of the QDs is engineered to reduce non-specific binding for a variety of applications, such as sensing, cellular imaging, and Förster Resonance Energy Transfer (FRET). These properties make QDs a unique class of light-emitting nanoparticles with promising potential in optoelectronics, biotechnology, and medicine. RayBiotech's quantum dots, ranging from 450-645 nm, have a high quantum yield (>50%) and are now available independently or in an easy-to-use kit format, allowing researchers to conjugate proteins & ligands of their own choice.