Can you reuse the lysis buffer after you add DTT and PMSF?

Thank you very much!!!

I highly recommend you to use lysis buffer with freshly added DTT and PMSF. DTT is a relatively unstable compound due to air oxidation. PMSF is also very unstable in aqueous solutions (110 min at pH 7, 55 min at pH 7.5, and 35 min at pH 8, all at 25°C). I usually make lysis buffer stock without DTT and PMSF. I aslo make 1M DTT and 100mM PMSF (in ethanol or isopropanol). When I start the experiment, I add DTT and PMSF freshly into the lysis buffer.