Searching for a technical bulletin? As of May 20, 2013, ARUP's technical bulletins have been replaced by ATIs or additional technical information documents. Attached to specific tests in ARUP’s Laboratory Test Directory (LTD), ATIs provide answers to frequently requested technical information and are easy to access and read. ATIs aim to answer your questions about test interpretation, additional tests to consider, or other technical aspects of a test, and may even save you a call to Client Services. Please view the video below for more information.