1. Coral Bleaching Experiment
Marcel Alcide
Yao Djilan
Leonard Desir
Lauren Campbell

2. Procedure 1) Determine the Zoox density
2) Chlorophyll extraction & measurement
3) Determine protein concentration.

3. 1) Determination of the zoox density
Weighed 4 polyps
7.7 x 10-3g
insertion of polyps into tube containing 2mL sea water.
Homogenize for 20 sec.
Measure the total homogenate volume/
4.3 x 108 zoox/g

4. 2) Chlorophyll extraction & measurement
Addition of 9mL of acetone to 1mL of homogenate into new tube
Vortex for 10 mn
Centrifuge for 5mn
Decantation
Calculation of the amount of chlorophyll

5. Calculation of the amount of chlorophyll
Wavelength
665nm →
647nm →
630nm →
Absorbance
0.03
0.015
0.019

6. Ca = (11.85A665)-(1.54A647)-(0.08A630)

7. Determination of the protein concentration
.1mL of .25 mg/mL BSA + 5mL Bradford
.1mL of .50mg/mL BSA + 5mL Bradford
.1mL of .75 mg/mL BSA + 5mL Bradford
.1mL of 1.00 mg/mL BSA + 5mL Bradford
.1mL of 1.25 mg/mL BSA + 5mL Bradford
.1 ml of homogenate+ 5mL of Bradford
Abs(avg)
.385
.641
.900
1.116
1.284
.074
Wavelength used: 595nm

8. Graph

9. Result
.074 = x
X = -.013

10. Discussion Why did we get a negative result?
The use of an insufficient amount of polyps could cause that to happen because the machine used to measure the absorbance is very sensitive. In the next experiment we will use a greater amount of polyps to see if we will get a positive result.

11. The End