I will endeavor to write more in active voice, but I think it’s appropriate to shift focus from who’s doing the action to what’s being done in some cases.

Case 1:Writing up your results for publication. Use active voice, because it makes for more natural sounding, easier to read sentences.

We assayed the samples for calcium, alkaline phosphatase, and osteoprotegerin.

The samples were assayed for calcium, alkaline phosphatase, and osteoprotegerin.

Case 2:Writing a grant proposal. The focus should be on what’s going to be done, rather than who’s doing it. Passive voice works here, because active voice would just be a bunch of, “We will …” phrases stuck on the beginning of every sentence, not adding much.

The choline deficiency model of hepatocellular carcinoma will be used to generate malignant cells.

We will use the choline deficiency model of hepatocellular carcinoma to generate malignant cells.