Blood Grouping By Tube Method
#### Tube Method
**Principle:**
The tube method involves mixing blood with antisera in test tubes and centrifuging to observe agglutination. This method is more sensitive and reliable than the slide method.
**Specimen:**
– Whole blood or RBCs suspension in isotonic saline.
**Apparatus and Reagents:**
– Test tubes
– Anti-A, Anti-B, and Anti-D sera
– Centrifuge
– Pipettes
– Isotonic saline
– Incubator or water bath (if available)
**Procedure:**
1. **Label the Tubes:** Label three test tubes as A, B, and D.
2. **Add Antisera:** Place one drop of Anti-A, Anti-B, and Anti-D sera into the corresponding tubes.
3. **Add Blood Sample:** Add one drop of blood or RBC suspension to each tube.
4. **Mix and Centrifuge:** Gently mix the contents and centrifuge at 1000 RPM for 1 minute.
5. **Resuspend and Observe:** Gently resuspend the cells and observe for agglutination.
6. **Interpret Results:**
– Follow the same interpretation guidelines as the slide method.
**Precautions:**
– Ensure proper mixing and avoid vigorous shaking to prevent hemolysis.
– Use a calibrated centrifuge and avoid excessive centrifugation which can cause false results.
– Perform the test at room temperature or as recommended by reagent manufacturer.
