I'm doing a project that needs to be done with adult (> 40 days) rats and the success rate is very low. I patched about 1 cell from 1 animal on average but only 1/3 cells can last long enough to give drugs. I kept having re-sealing problems. I tried many methods from other papers and wrote to those labs. They gave me all kinds of suggestions and tips. Still I got success some days and failure other days. I know the success rate on old animals is low but have no idea how good it can be. My boss kept blaming me for not getting good result contineously. Wheneve I didn't succeed I have to make some change, otherwise she would critisize me not making any effort. I'm reluctant to change my protocol too much because it still works (not as well as expected though).
Can anybody who is doing similar experiment give me a hint? If the success rate is as low as what I got now, I'll stay on my current method. Otherwise I need to figure out what's wrong and improve it. Thanks a lot.
success rate of patching old animals