Mixing young blood with old may help reverse ageing effects.

A new study led by scientists from Harvard Stem Cell Institute in Boston has shown that mixing blood from young people with the one from elderly might help reverse effects of ageing.

Lead researcher Amy Wagers discovered that the blood of the young animals seemed to rejuvenate ageing blood stem cells in the bone marrows of the older mice.

It also revitalised so-called "niche" cells in the bone marrow, which nourish, support and stimulate blood stem cells. Although old mice make more blood stem cells and more niche cells than young mice, many are faulty.

"The reason the old animals have too many is probably an attempt to compensate for these flaws," New Scientist quoted Wagers as saying.

Old mice also make too many myeloid blood cells, which contribute to inflammation and the development of cancer, and too few lymphoid blood cells, which orchestrate tissue repair.

Mixing young blood with old may help reverse ageing effects.

Now, 'dipstick' test to determine blood type.

Scientists have developed what they say is the first 'dipstick' test which can instantly determine blood type of a patient or donor.

The inexpensive and portable test involves placing a drop of blood on a specially treated paper strip which then changes colours to determine the type of the blood.

Australian scientists, who reported their research in the American Chemical Society's journal Analytical Chemistry, said the new blood testing method could be a boon to health care in developing countries.

"The test also could be useful in veterinary medicine, for typing animals' blood in the field," they noted.

Now, 'dipstick' test to determine blood type.