It depends on where you are applying from. When I applied at the Washington DC embassy, I transferred the money from my business account to my personal account a few days before I applied, then transferred it back when it was approved. I wasn't questioned about it.
My gf, who is a nurse, had no problem getting a tourist visa to USA. The main thing she got was a letter from the hospital saying how long she worked there and that she was expected to return to work after her trip.