Most Americans are willing to donate samples of their body tissue for use in research, but their willingness drops when they're told about possible morally charged uses of their specimens, a new study finds.

Researchers surveyed nearly 1,600 adults, and found that 68 percent said they would donate tissue samples to a biobank, which is a facility that stores biological samples for use in future research. What's more, these participants also agreed that their tissues could be used in any future research, without additional consent.

But when participants were told about the possible ways that researchers might use their samples, their willingness to donate declined. For example, when asked if they would donate to a biobank even if their samples could be used to develop "more safe and effective abortion methods," only about half (49.5 percent) of participants agreed. [Top 3 Techniques for Creating Organs in the Lab]

About 64 percent said they would donate even if their samples were used to develop kidney stem cells that would be grown in pigs, and 55 percent said they would donate even if their samples were used to develop patents and earn profits for commercial companies.

Currently, most biobanks get their materials from people undergoing medical tests, and ask just once for a person's permission to use their tissue samples in research. If the donor gives consent, this is considered to apply to all future uses of the tissue (an approach referred to as "blanket consent").

But as more people are asked to donate to biobanks, moral concerns like those listed in the study "may need to be addressed to moderate possible effects on donation rates," the researchers said.

The survey also asked participants about their views on five different methods for obtaining consent to use tissue samples. About 56 percent said the blanket consent option was acceptable, but nearly 38 percent considered it the worst option.

But even more people (45 percent of those surveyed) said the worst option was asking participants for consent each time their tissues were used in any research project.

"This suggests that an adequate approach for dealing with donors' moral concerns may lie between these two extremes," the researchers said. For example, 70 percent of participants agreed with an option that asked donors for a one-time consent, but allowed them to review current research projects being done, and withdraw their samples if they saw any projects that worried them.

The study, conducted by researchers at the University of Michigan Medical School and Michigan State University, is published Jan. 27 in the Journal of the American Medical Association.

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