Procedure

1. The safety equipment was put on.
2. 1.5mL of the blood samples was injected into the 5 tubules.
3. Each tubule was injected with 0.5mL of saline solution.
4. One tubule containing a blood sample was to be left alone for comparison.

       

1. The second tubule was mixed with pH 4 buffer solution.
2. The third tubule was mixed with pH 10 buffer solution.
3. The fourth tubule was mixed with 1 mol/L HCl solution.
4. The fifth tubule was mixed with pH 7 buffer solution.

       

1. The physical observations of each reaction were recorded by hand.
2. Each blood sample was examined through a machine for 20 minutes.
3. The results were printed out automatically from the computerized machine.