Determination of OXA concentration by ICP-MS
We added 200 μL of HNO3 and 400 μL of
H2O2 into the lysate of the collected
cells, DRGs, or tumours; the mixture was incubated for 2 h at 80 ℃.
Next, 200 μL of 25% ammonia solution was added, and the volume of the
solution was adjusted to 4.0 mL with ddH20. Finally, the
concentrations of OXA were determined
by inductively coupled plasma mass
spectrometry (ICP-MS, PerkinElmer Nexion 300X) after the solution was
filtered using a film filter (0.22 μm). The OXA content was determined
relative to the total protein content for cells or relative to the
weight for tissues.