How are blood groups differentiated? Premium
The Hindu
Human blood is classified into groups based on antigens and antibodies, with the AB group being the universal recipient.
A: Human blood consists of red blood corpuscles as a constituent, which gives it its red colour. On the surfaces of these red cells are present one or both of two types of antigens (proteins), designated A and B. Other than these, two antibodies, designated as antibody-A and antibody-B, present in the serum, are also involved in the classification of human blood. (Serum, a constituent of blood, is a straw-coloured liquid that can be seen after removing all the other blood cells from a sample.)
Antibodies have the property of clumping red cells. When antigen-A is present on the red cells, the serum contains only antibody-B, which will clump red cells having antigen-B on their surface. Then the blood is classified as group A.
When antigen-B is present on the red cells, the serum contains only antibody-A, which clumps red cells having antigen-A. As a result the blood is classified as group B.
In some people, both antigens A and B are present on all the red cells, so their serum does not contain any of the antibodies. They belong to the AB group. Their blood cells don’t clump whether they receive A group or B group blood. That is, A and B are compatible with the AB group.
The fourth type, O, has neither of the antigens on its red cells but has both antibodies in the serum.
In order to keep red cells from clumping, those with A group blood can receive blood only A and O group blood, and those with B group only B and O group blood. But the AB group can receive blood from any of the groups. Thus it is called the universal recipient. Similarly, those with O group blood are universal donors.
This system of classification is called the ABO system. Blood groups are also classified by the Rhesus system (Rh). The-Rh factor leads to one type in which the Rh factor is present (Rhesus positive) and another in which it is not (Rhesus negative).
What began as a routine one-week mission for astronauts Sunita Williams and Butch Wilmore aboard Boeing’s Starliner capsule quickly escalated into an unexpected eight-month stay in space. After a successful launch in June 2024, their mission faced multiple technical failures, including thruster malfunctions and helium leaks, making it too risky to return using the Starliner. NASA’s solution? Delay their return until early 2025 aboard SpaceX’s Crew Dragon capsule. Despite the extended mission, Williams and Wilmore remained resilient, continuing their work on the ISS as NASA worked to resolve the situation.
The story of the first-of-its-kind collaboration between award-winning Indian couturier Rahul Mishra and Italy’s multimillion-dollar fashion house Tod’s goes back to 2017 when their paths crossed in Paris. The latter reached out to Rahul — who had created waves in the industry with his couture edits at platforms like Paris Fashion Week — for a limited-edition handcrafted capsule of bags and shoes, which provoked his fiercely creative mind to take up the challenge. Made with absolute luxury of time and embroidered with intricate details, the Rahul Mishra X Tod’s has been launched today, during London Fashion Week, at Tod’s Bond Street Boutique.