The bluish slime in the tube is DNA extracted from human saliva. Due to the use of detergent it is bluish in color. Apart from detergent, distilled water, ethanol and salt were used to complete the process.
<a href="//commons.wikimedia.org/wiki/User:S_Shamima_Nasrin" title="User:S Shamima Nasrin">S Shamima Nasrin</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>