Data grids are middleware systems that offer secure shared storage of massive scientific datasets over wide area networks. In this paper we describe the GRelC Data Storage, a novel grid storage service which has been developed within the Grid Relational Catalog (GRelC) Project. The aim of this service is to manage efficiently, securely and transparently collections of bioinformatics data concerning "in silico" experiments on the grid promoting flexible, secure and coordinated storage resource sharing and publication across virtual organizations, taking into account current grid standards and specifications.