Mayo Clinic to expand biorepository Mayo Clinic has launched an $11.6 million expansion of its John W. Marvin Building at 2915 Valleyhigh Dr. NW to add much needed storage space for a growing number of genetic biosamples. The expansion will add 39,000 square feet of space to the 176,455-square-foot biorepository. Written By: Jeff Kiger | × Mayo Clinic has launched a $11.6 million expansion of its John W. Marvin Building at 2915 Valleyhigh Dr. NW in Rochester to add much needed storage space for the growing numbers of genetic biosamples. The expansion will add 39,0...