By Josh Keller

San Francisco

In response to a wave of criticism, the University of California at Berkeley is modifying one aspect its controversial plan to allow many freshmen this fall to submit a personal DNA sample, a campus official said on Tuesday.

Berkeley's largest undergraduate college will continue to encourage new students to participate in the program, which is intended to teach students about genetic medicine by providing anonymous, limited tests of their DNA. But officials have decided to drop a plan to give more-extensive DNA-testing kits as prizes to four students.

Those more-extensive testing kits, which were donated by a company called 23andMe, were one target of critics who argued that Berkeley's DNA program was ill-advised. In a letter last week, the president of the Council for Responsible Genetics, a nonprofit group that encourages public debate about the social, ethical and environmental implications of genetic technologies, wrote that giving out the commercial testing kits "raises serious questions of independence and academic integrity."

The university made its decision after hearing concerns about the kits from some faculty members, said Alix Schwartz, director of academic planning for the undergraduate division of the College of Letters & Science. Four winners of a contest to best illustrate the theme of personalized medicine would have received the testing kits.

"We suddenly realized that handing an 18-year-old a genetic kit without counseling, there might be something from that test that we don't want to be responsible for," Ms. Schwartz said.

Instead, Berkeley will give out $1,000 as a top prize and $500 each for the next three prizes, she said.

The voluntary DNA testing program will otherwise continue as planned, she said. That test, which will be mailed out to new students next month, is limited to three genes that relate to the ability to metabolize alcohol, lactose, and folates.