I am working with nuero2a cells and treating them with a protein that has been prepared in DMSO (3)%. I am wondering at what percentage might this DMSO kill my nuero2a cells.
I can't say for Neuro2a specifically, but DMSO is usually tolerated with little or no observable effects at 0.1% final concentration (v/v). At 1% or higher, effects on cell behavior have been reported.
Is your protein/peptide in 100% DMSO, and you are diluting it 33-fold for a final concentration of 3% DMSO, or is your protein in 97% aqueous solution, 3% DMSO? If the latter, then try to make sure your protein stock is at least 30x more concentrated than the working concentration. If the former, you may need to try to change solvents or concentrate your protein before use.
Just did an experiment, where 1.6% DMSO turned out to be pretty toxic for colon cancer cells. Because we did not titrate lower, it basically scrambled the experiment.
Again learned the hard way to never forget to do the proper controls, even if you think about saving yourself the work of these extra wells.
I did an experiment where I used 2% DMSO in SH-SY5Y cells and I saw almost 50% cell death. I did not do the calculations right that's why I ended up having 2% DMSO per well.
I repeated with correct calculations and reduced the final concentration of DMSO to 0.01%. No cell death in Control.