I started my masters with semi finished experiment by my supervisor, and h suggested to do more experiments to include them in my thesis. However, after year and a half, the other methods we were using failed to show any results (the cells were not growing)! My supervisor told me not to worry and he will let me have the previous results and methodology to be in my thesis since we couldn't conduct more experiments on other specific cells. My question: is it ok to do so? I haven't done that experiment myself!
This is ok (happens all the time, because usually you do not have severaly years for a big project), as long as you make sure the your citation is done right. Just don't claim you did the other experiments and you will be fine. (I know this should be clear. I just mentioned it, because I know of a case where that apparently wasn't clear enough...)