The Chemical Entities of Biological Interest (ChEBI) ontology is downloaded weekly from EMBL-EBI at http://www.ebi.ac.uk/chebi/. The data is made available under the Creative Commons License (CC BY 3.0, http://creativecommons.org/licenses/by/3.0/). For more information see: Degtyarenko et al. (2008) ChEBI: a database and ontology for chemical entities of biological interest. Nucleic Acids Res. 36, D344–D350.
An organic molecular entity (structure not reported) that is a fluorescent dye with a maximum absorption wavelength at 632 nm and emission wavelength 647 nm. It is a bright and photostable far-red dye with excitation ideally suited to the 633 nm laser line. Alexa Fluor 633 succinimidyl ester is not suitable for labeling nucleic acids.