Celtarys Research is a biotechnology startup based in Spain, founded in 2021. The company's slogan "Innovative Chemistry to Illuminate Biology" encapsulates its focus on developing and commercializing chemical tools to expand the use of fluorescence-based methods in drug discovery. One of Celtarys Research's key offerings is its chemical conjugation technology, which enables the rapid (customized fluorescent ligands with optimal pharmacological and photophysical properties for a wide range of druggable targets. The company has initially utilized its technology to create a catalogue of 20 fluorescent ligands tailored to different families of G-protein-coupled receptors (GPCRs), including adenosine, dopamine, serotonin, cannabinoid, and muscarinic receptors. These ligands are characterized by their flexibility, efficiency, high affinity, and selectivity for the target, as well as a wide variety of fluorochromes. Moreover, they are compatible with various assays such as FRET, polarized fluorescence, high-content screening, and flow cytometry. Celtarys Research also provides custom synthesis services for specific fluorescent ligands targeting therapeutic potential. In September 2021, the company secured a €650.00K Seed Round investment from VIGO ACTIVO SOCIEDAD DE CAPITAL RIESGO DE REGIMEN SIMPLIFICADO SA and Xesgalicia. The funding will likely bolster the company's R&D efforts, expand its product offerings, and support its commercialization strategies. Celtarys Research's innovative approach to leveraging chemistry in the field of biotechnology positions it as a promising player in the realm of drug discovery, with potential for significant impact in the pharmaceutical industry.