Biology Lab Report (Format Example)

Ellen Herrington
Claire Jones TA
15 October 2017

Sodium Chloride: The Ankistrodesmus Algae Killer


This lab report depicts the results of the pollutant, sodium chloride, on freshwater, small-pond Ankistrodesmus Algae when mixed together in test tubes and examined over a two week period. The hypothesis suggests that, by the end of the two week period, all the algae contained in the test tubes will have died, making sodium chloride an inhibitor of the growth of algae (Tonn, S., 2016).


Four out of eight test tubes were set aside to be used as blanks for this experiment. A 500mM of 100mL sodium chloride solution was prepared and divided equally into four test tubes, along with a differentiating amount of Alga-Gro and Ankistrodesmus algae, decreasing by half of the existing amount each time. (ex. 100/2=50%, 50/2=25%, etc.) Three of the remaining test tubes received a mixture of Alga-Gro and sodium chloride, each containing a diluted portion of pollutant. The last test tube received 100% Alga-Gro. All test tubes were labeled accordingly. Once each test tube was filled, the spectrophotometer was set to 450nm and their initial wavelength was recorded, and the test tubes were placed back into the holding tray. After a week’s time, the test tubes were placed back into the spectrophotometer, and the absorbed wavelength was recorded, and the process was repeated again during the two week mark.

Results and Discussion

Black- Day 0
Red- Day 7
Blue- Day 14


Shown above are the results from the experiment. As shown from from the chart, at the two week mark, each test tube decreased on average, except for Tube 2A and 2B, which contained the same amount Alga-Gro and pollutant. One possible flaw in this experiment was that the test tube caps were not opened slightly, allowing for air to come into the tube and give it oxygen. One potential flaw in the experiment could be that the test tube caps were not opened slightly to allow air into the tubes for the algae to obtain oxygen. A way to enhance the accurately of this experiment would be to elongate the period of time to measure the wavelengths produced by the algae. Instead of two weeks, it may be increased by four.

Shara, Tonn.

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