PCRM Develops World’s First Cruelty-Free Insulin Assay
Each year, U.S. doctors and researchers order innumerable blood tests for patients with diabetes or suspected diabetes. As laboratories analyze the insulin levels in patients’ blood, they employ an assay procedure that uses cruelly produced animal-derived ingredients. There has been no available alternative—until now.
In January 2004, PCRM president Neal Barnard, M.D., launched an important clinical trial to test the effect of a low-fat, vegan diet on patients with type 2 diabetes. Unfortunately, the laboratories he contracted with for clinical tests measured insulin in a particularly gruesome way. They used antibodies to detect insulin, and these antibodies were produced from cells that had been placed into the abdomens of living mice. The unfortunate animals become painfully swollen with antibody-filled fluid, which the laboratories extract with a needle and use in test kits. Considered “living factories,” these animals are used by the millions each year, not just for insulin assays but for all types of medical tests.
Where There’s a Will, There’s an Alternative
Rather than support this form of animal use, PCRM decided to look for a lab that could grow the antibody-producing cells in a test tube. Working under Dr. Barnard’s direction, PCRM research analyst Megha Even, M.S., took on the challenge. She soon located a laboratory in Emeryville, California—BiosPacific—that was willing to try to grow the cells in the test tube, rather than in mice.
But another obstacle stood in the team’s way. Growing antibodies in test tubes typically requires the use of fetal calf serum as a growth promoter. Calf serum is a gruesome byproduct of the slaughterhouse industry, and it has been hotly controversial, not only for the cruelty involved in its production, but also for its possible contamination with mad cow prions or other disease carriers. Fetal serum is also as biologically variable and unstandardized as it is cruel. So the PCRM team asked BiosPacific to work out a system of cellular growth promotion that sidestepped fetal calf serum.
Was it possible not only to grow the cells entirely in the test tube, but to do so without the usual growth factors in fetal calf serum?
It took months of work, and the process was not cheap. But it eventually became clear that, indeed, the cells grew perfectly well with this method and produced the antibodies the team needed.
A Second Hurdle Overcome
The next challenge was to incorporate these antibodies into a test kit. To do that, PCRM worked with Linco Research of St. Charles, Missouri, one of the leading suppliers of insulin kits. It was several months before the kit was ready. Finally, several human blood samples were tested using the new system, and the results were compared to the existing insulin assays. When the data came in, the laboratory called PCRM to tell them the news: The new test was every bit as accurate as the old one—or perhaps just slightly better.
The new method is now being used to analyze insulin levels in PCRM’s study participants’ blood samples. Even is now working on two scientific papers describing the project. Once published, the papers will promote the use of PCRM’s new custom assay and encourage researchers to develop alternatives to other tests that use animal-derived ingredients.