Last Revised: November 18, 2025
Use a vacuum flask to collect the supernatant generated during the procedure and keep adding spent media and wash buffers, which will further dilute the ACK buffer content. Once the protocol is complete, aspirate bleach into the collection flask while maintaining vacuum. This step will decontaminate the collected ACK waste. The sealed waste flask ensures that any hazardous byproducts remain contained and unavailable to researchers or bystanders. Then, proceed with pouring the content down the drain after the process is concluded, or continue using the same collection flask to aspirate more spent media and wash buffers as usual.
Please remember that a good laboratory practice is to discard the contents of the collection flask daily and to avoid overfilling it. Always leave sufficient space for the final bleach step. After adding bleach and allowing for a 30 minute incubation period, the decontaminated waste can be safely poured down the drain.
Other options are collecting the ACK buffer supernatant in a beaker and performing the bleach decontamination inside a fume hood.
For questions, contact ehrs@ehrs.upenn.edu.