A team of scientists has invented a new ultra-fast, low-cost, paper strip test that can identify a person’s blood type in just 30 seconds.
Knowing the blood type of a patient is of utmost importance in emergency situations but existing blood tests are too slow to be of any use in such cases. They can take anywhere from 5 to 20 minutes to correctly verify someone’s blood group.
As a result, emergency departments have to stack up on only O type blood which can be safely given to anyone. However, this creates too much reliance on a single type of blood type and can prove problematic in the near future.
“The demand is already extremely high and it’s getting higher,” says Janet Wong at the Australian Red Cross Blood Service, which collects blood donations in Australia.
Hong Zhang at the Third Military Medical University in China has, along with his colleagues, developed a paper-based test that can be performed quickly and accurately. Moreover, it is also cost-effective and can be performed right at a patient’s bedside without any specialized training or equipment.
“When trialled on 3550 human blood samples, the low-cost strip was more than 99.9 percent accurate, and only took 30 seconds to complete.”
How Does it Work?
To those interested in the workings behind this new test, it relies on the antigens that are present on the surface of red blood cells. The Type A blood contains red blood cells with A antigens, while B have B antigens. Meanwhile, Type AB has both, and O has none.
There is also a separate D antigen that is responsible for determining if the blood type is “positive” or “negative”, also known as rhesus positive or negative.
This paper strip is impregnated with a matrix of antibodies and dye. When it is brought into contact with a drop of blood, squares of color develop as the blood spreads across the strip and reacts with the antibodies. For each antigen, a teal square shows up if it is a present, or a brown square if it is not.
“We are expecting that we can see this product in the market within 1-2 years,” says Zhang.
He also said that the paper strip can be best used as an alternative method to blood testing in war zones or remote areas where there are no labs to test patients’ blood types.