During a December 2021 presentation, Matthew Lotti (senior research associate in analytical development at Ultragenyx) highlighted difficulties with determining adenoassociated virus (AAV) capsid titers during gene therapy production. With support from Gyros Protein Technologies, Lotti spoke about his team’s development of a method for measuring AAV titers using a Gyrolab xPand immunoassay system. Lotti’s Presentation Simple analytical methods such as UV spectrophotometry measure capsid titers most effectively after virions have undergone purification. To test samples from earlier process stages, Ultragenyx…