Testa studied physics at University of Genoa in Italy and graduated with a M.Sc. in 2005. In 2009, she earned her Ph.D. in Biotechnology. During her Ph.D., she worked on quantitative methods in single-molecule biophysics and studied transitional states in fluorescent proteins. After completing her thesis, supervised by Alberto Diaspro, she joined Stefan Hell 's research group at the Max Planck Institute for Multidisciplinary Sciences in Göttingen, Germany as a postdoctoral researcher where she had already spent part of her doctoral studies.