1Department of Zoology, Govt. Model College, Dhanora, Dist. Durg
2Department of Zoology, Govt. NPG Science College, Raipur
3Department of Zoology, SNA Govt. Arts & Commerce College, Kohaka-Neora, Raipur
4Human Resource Development Centre, Pt. Ravishankar Shukla University, Raipur, 492 010
Early in the twentieth century, a most important discovery was made in blood transfusion when Karl Landsteiner showed that by cross-testing one blood sample with another, some samples would mix successfully with no visual signs of reaction while others would react strongly, causing agglutination, which is a massive clumping of the red cells.
