The Library of variants (LOV) v. 1.0 CD-Rom is a digital library of more than 200 typical cation-exchange HPLC graphs, for the phenotype determination of a haemoglobin disorder. These graphs, presented on a case-report form, have been obtained with the 4 Bio-Rad liquid chromatography devices available for haemoglobin analysis: D-10, Variant, Variant II and Variant nbs. In case of an atypical HPLC pattern obtained in clinical practice, this library will be of a potential useful help for the biologist to make a presumptive diagnosis of the type of haemoglobinopathy. Nevertheless, the definitive characterization will have to be made by molecular biology in a reference laboratory.