Current Events (IMAGE) Arizona State University Caption Measurements of tunneling current plotted against time for guanine-cytocine base pairs and for adenine-thymine pairs. Tunneling current for A-T pairs persists for a shorter duration, falling off precipitously compared with the same measurements for C-G pairs, which are held together with 3 hydrogen bonds. Credit Biodesign Institute at ASU Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.