CALIFORNIA'S Supreme Court has just offered a compelling reminder of the promise of biotechnology -- and of the obsolescence of the law that now governs it. John Moore, who was a cancer patient at the UCLA Medical Center 14 years ago, sued his doctors and the center after his diseased spleen was removed and its cells were altered genetically and used in research. That research proved to be very profitable, and Mr. Moore sought a share of the money. The defendants, comparing Mr. Moore's position to that of the person who sold Michelangelo his paints, persuaded the court that he had no property rights in the results of the research. But the court ordered a trial on the question of whether the doctor properly obtained the informed consent of the patient before the operation. If Mr. Moore can prove otherwise, he may yet collect damages.

If the court had decided the property question the other way, much research in biotechnology would have been jeopardized. That could still happen if a court in another state rules differently, for this week's decision applies only in California. Different outcomes are possible because the federal government has not regulated research, commercialization or property rights in biotechnology by statute. More than three years ago the Congressional Office of Technology Assessment saw this problem coming and published a report outlining a number of options for action to regulate the use of human tissues and cells in biotechnology, but nothing was done. Similarly, Congress has left to the courts matters involving the patentability of material developed from such living microorganisms as plants and animals. Here the judges find themselves working with a section of the patent law that was written by Thomas Jefferson.

Research is not being conducted in a regulatory vacuum. The industry needed and wanted regulation, for biotechnology is at the same time potentially dangerous and potentially profitable. It is important that clear lines be drawn to govern responsibilities, liabilities and commercial rights. But the Reagan administration's preference was to avoid making new law and to rely on existing departments and regulatory agencies to oversee this area piecemeal. Periodically, though, it's a good idea for Congress to review the field and reassess the state of federal regulation.

In a short 15 years or so, biotechnology has had a broad impact. Research is now underway in fields as diverse as cancer and AIDS cures, a super-producing dairy cow and a better tasting tomato. Because of the great public interest in these new products and their orderly development, Congress needs to take a careful look at the law and adapt it to the astonishing possibilities that science is rapidly creating.