1 NEW METHODS FOR THE CONCENTRATION OF VIRUSES FROM 1 URBAN SEWAGE USING QUANTITATIVE PCR 2 3 Byron Calgua a,1 , Jesus Rodriguez-Manzano a,1 , Ayalkibet Hundesa a , Esther Suñen b , 4 Miquel Calvo c , Sílvia Bofill-Mas a , Rosina Girones a, * 5 6 a Department of Microbiology, Faculty of Biology, University of Barcelona, Av. 7 Diagonal 643, Barcelona 08028, Spain 8 9 b Department of Immunology, Microbiology and Parasitology, Faculty of Pharmacy, 10 University of the Basque Country, Paseo de la Universidad 7, Vitoria-Gasteiz 01006, 11 Spain 12 13 c Department of Statistics, Faculty of Biology, University of Barcelona, Av. Diagonal 14 643, Barcelona 08028, Spain 15 16 1 These authors contributed equally to this work 17 18 * Corresponding author at: Department of Microbiology, Faculty of Biology, 19 University of Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain. Telephone 20 number: (+34) 93 402 1483. Fax number: (+34) 93 403 9047. E-mail address: 21 rgirones@ub.edu 22