[citation needed] His main work[2] is in the field of protein sequence analysis and more particularly in the development of databases and software tools for this purpose.

The Swiss-Prot database is the primary protein sequence resource in the world and has been a key research instrument for both bioinformaticians and laboratory-based scientists in a very wide range of applications.

[24] What was intended as a prototype grew rapidly into a major site that provides access to the many databases produced partially or completely in Geneva as well as many tools for the analysis of proteins (proteomics).

[25] In November 1997, together with Ron Appel and Denis Hochstrasser, he founded GeneBio (Geneva Bioinformatics SA), a company involved in biological knowledge.

[26] Since 2009, in the framework of the CALIPHO group, directed by himself and Lydie Lane, he is involved in the development of neXtProt[27][28][29] a resource which aims to provide life scientists with a broad spectrum of knowledge on all human proteins.