The blood transfusion is a way to add blood to the body after an illness or injury, This potentially life-saving procedure if done properly can save lives and can replace blood loss due to an illness, or injury.
Blood transfusion, if performed promptly, is a potentially life-saving intervention for someone losing a lot of blood. However, blood comes in several types, some of which are incompatible with others. Transfusing an incompatible blood type can severely harm a patient. It is, therefore, critical for medical staff to know a patient's blood type before they perform a transfusion.
A novel lab-on-a-chip device reveals the blood type within minutes, holding much potential for use in an emergency.
There are four major blood types — O, A, B, and AB. These types differ based on the presence or absence of structures called A antigens and B antigens on the surfaces of red blood cells.
Blood can be further divided into positive and negative types based on the presence or absence of D antigens on red blood cells. Medical professionals usually tell a patient's blood type with tests involving antibodies against the A and B antigens. When antibodies recognize the corresponding antigens, they bind to them, causing the blood cells to clump together and the blood to coagulate. Thus, specific antigen-antibody combinations tell us what is the blood type of blood sample.
Yet, while the concept sounds straightforward, the equipment and techniques required are often very specialized. Tests, therefore, are non-portable, have high personnel cost, and can take over half an hour to yield results. This can prove problematic in several types of emergency situations.
Aiming to solve these problems, a team of scientists at Japan's Tokyo University of Science, led by Dr Ken Yamamoto and Dr Masahiro Motosuke, has developed a fully automated chip that can quickly and reliably determine a patient's blood type. In the words of Dr Motosuke, he and his colleagues "have developed a compact and rapid blood-typing chip which also dilutes whole blood automatically."
The chip contains a micro-sized "laboratory" with various compartments through which the blood sample travels in sequence and is processed until results are obtained. To start the process, a user simply inserts a small amount of blood, presses a button, and waits for the result.
Inside the chip, the blood is first diluted with a saline solution and air bubbles are introduced to promote mixing. The diluted blood is transported to a homogenizer where further mixing, driven by more intensely moving bubbles, yields a uniform solution. Portions of the homogenized blood solution are introduced into four different detector chambers. Two chambers each contain reagents that can detect either A antigens or B antigens. A third chamber contains reagents that detect D antigens and a fourth chamber contains only saline solution, with no reagent, and serves as a negative control chamber in which the user should not observe
any results.
During testing, the research team screened blood samples from 10 donors and obtained accurate results for all 10 samples. The time needed to determine a single sample's blood type was only five minutes.
