Harvard University researchers said on Wednesday they were seeking permission to use cloning technology to make human stem cells.

They plan to use technology similar to that used by South Korean scientists, who announced in February they had cloned a human embryo as a source of valuable stem cells.

It would be a first step toward personally tailored medical treatments for diseases such as juvenile or type 1 diabetes, Alzheimer’s and Parkinson’s disease.

“We are seeking permission to do a process called somatic cell nuclear transfer, often referred to as therapeutic cloning,” said Dr. Charles Jennings, executive director of the Harvard Stem Cell Institute.

The method is similar to that used to make Dolly, the sheep, the first cloned adult mammal. An egg cell is cleaned out to form a shell and a nucleus is inserted from a cell from the animal or person to be cloned.

A chemical trigger starts the egg growing and dividing as if it had been fertilized by a sperm. After a few divisions, the ball of cells that results is made up mostly of embryonic stem cells.

Each one of these has the potential to form any kind of cell in the body, given the right nurturing and direction. They can grow in batches, or cell lines, for years without dying.

Scientists want to study both these embryonic stem cells, as well as adult stem cells, to test new medical treatments and to understand the basic biology of diseases.

Current law prohibits the use of federal funds to make human embryonic stem cells, and in August 2001 President Bush said scientists using federal funds could work only on a few already existing cell lines.

Earlier this year Harvard scientists, led by stem cell researcher Dr. Doug Melton, announced they had used private funds to create new lines of embryonic stem cells taken from embryos left over at fertility clinics.

Many anti-abortion groups support research on these types of stem cells, noting that the embryos at the IVF or test-tube clinics would be destroyed anyway. A majority in both houses of Congress supports it, too, and members have urged Bush to change his policy.

The Bush Administration argues that people who oppose experimenting on human embryos should not have their tax dollars used in such research, but it is silent on what privately funded groups can do.

Using cloning technology is much more controversial, although many groups support it.

Stem cell research has extended into this year’s presidential election, with Bush opposing it and Democratic challenger Sen. John Kerry strongly in favor of all embryonic stem cell research.

Jennings said Harvard had raised “substantial” funds for the experiment from private philanthropies, but declined to name them. “There are a lot of people who have the resources and who are very keen to see this sort of work go ahead,” he said in a telephone interview. “This is not commercial research.”

The Institute has asked Harvard’s Institutional Review Board to move ahead with the research. An IRB checks the ethics and scientific underpinnings of proposed research.

Patients at Harvard Medical School’s network of hospitals would be the ones to be cloned, with the clear understanding that their cells would be used only for basic research, not for any form of treatment, Jennings said.

He stressed that Harvard opposes the use of cloning technology to make live babies.