Chemical Structure of 4-(2-Hydroxyethyl)-1-piperazineethane sulfonic acid (HEPES).
<a href="//commons.wikimedia.org/wiki/User:Tsuruya" title="User:Tsuruya">Tsuruya</a>
2012-09-24 01:28:54
<span class="int-own-work" lang="en">Own work</span>