One of these substances called TE additionally chelates magnesium ions, making it ideal for storing (15[2])DNA. (15[1])Britton and Robinson name a “universal” one of these substances. Citrate and phosphate are found in one of these substances named for McIlvaine, which is mixed with glycerol to create mounting medium. CAPS, MOPS, and HEPES are three in a series of twenty of these agents used in biology named (15[1])for Norman (*) Good, most of which are zwitterionic compounds. The bicarbonate system in blood acts as one of these agents. The capacity of these agents is highest when their pH equals their pKa, which is a consequence of the Henderson-Hasselbalch equation. For 10 points, name these solutions that usually consist of an acid and its conjugate base to keep pH constant. ■END■