Fast mad cow test for live cattle in works

SAPPORO (Kyodo) A team of scientists at Hokkaido University is developing an automated device to detect mad cow disease using blood samples from live cattle.

The team, led by Mamoru Tamura, a professor at the university's Research Institute for Electronic Science, hopes to develop the device by this summer.

Detecting mad cow disease in young cattle is considered difficult because the type of protein, called prions, found in the brain of infected cows accumulates as the animals age.

The scientists said the new device will pave the way for establishing a faster and more accurate testing method for mad cow disease, formally known as bovine spongiform encephalopathy.

Under the current system, Japan tests all cows by taking brain tissue samples when animals are slaughtered.

A method called ELISA, or Enzyme-Linked Immunosorbent Assay, is used for the initial test before government agencies verify the results during the second-phase test.

ELISA involves adding enzymes to brain tissue samples but requires some manual work and takes four to five hours to get the results. The new testing method being developed by the Hokkaido team is conducted by adding prion antibodies and fluorescent dye to blood samples. The team then irradiates the samples with a laser to measure how fast the dyed antibody molecules move.

The fully automated testing measures the speed of the molecules' movements and displays it on a monitor. The team says prions, when combined with antibodies, are likely to grow into larger molecules and move slower than the lighter, normal molecules.

The test takes no longer than 90 minutes to get the results and is about 10 times more sensitive than the ELISA method, the team says.