Can human subjects be paid using a researcher's personal funds? I want to conduct some research and will apply for IRB approval. But, finding money to offer incentives for respondents may be difficult. I do not mind using personal funds as the total amount is very low. 


Is there any ethical issue with using personal funds for research?
Do you know of any IRB related regulations that address the above issue?


If it matters I am at a US educational institution.
I've sat on an IRB panel and we've never been concerned about the source of funds for participant gift-cards.

p.s. Note I'm an ethnographic fieldworker and I often buy small gifts for the families and individuals who participate in my projects. It's too much of a pain to pay for these out of my research account (why do you want 15 stuffed bears and keychains?) so I buy them out of pocket.