Watchara discovered the monoclonal CD4 antibody and developed a test kit called CD4 Select that can be applied to blood-analysis devices at general hospitals without using the expensive cytometer, which is used to examine cells in fluid.

Prasit said the strip test was the first of its kind in the world.

Testing the absolute number of CD4 positive lymphocytes is important in treating Aids patients because it helps to assess the state of the disease, prognosis and treatment, according to Prasit.

The current standard test requires a flow cytometer and a special reagent. This limits its availability to major hospitals, while patients cannot easily access it and face high costs from sending blood samples, Prasit said.

Watchara said the Bt300 strip test was as effective as cytometric analysis but nearly 50 per cent cheaper. It could yield a result in just one hour, compared to four hours for the cytometer.

Biotec deputy director Darunee Edwards said the new test would be very useful in treating Aids patients.

The centre has transferred the technology to iMED Laboratories, a Thai diagnostic test manufacturer, to produce and distribute the test kit so that it can be thoroughly accessed.

The test kit should be on sale late this month. Biotec has already obtained a patent in Thailand and is applying for patents in the United States and other countries.