User:Paola Quinones Lopez/Notebook/Lab 2
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Prof. Moriarty Bio 210-009 28 January 2015 Lab 2: Identifying Algae & Protists
I. Introduction The purpose of this experiment is to identify unknown protists from the Hay Infusion using the Dichotomous Key in order to identify them and to define characteristics of protists and algae. Another objective is to characterize bacterial diversity in Hay Infusion by performing a serial dilution.
II. Methods and Materials Dichotomous Key was used to determine the organisms’ identity. In order to do that, a wet mount was made from the Hay Infusion’s top, middle and bottom niche. The three samples were observed in the microscope. For the serial dilutions, four tubes were used in which10mLs of sterile broth were poured into each labeled tube (10-2, 10-4, 10-6, 10-8). Eight plates were labeled the same as the tubes, only that four of the plates were added nutrient agar and the other four nutrient agar plus tetracycline. One plate from each group was labeled 10-3, 10-5, 10-7, 10-9. 100micro/liters were pipetted from the Hay Infusion to the 10mLs of sterile broth into the tube labeled 10-2. 100micro/liters of broth from tube 10-2 were passed to tube10-4. The same thing was done for 10-6 and 10-8 serial dilutions. Serial dilutions on the plate were made by pipetting 100micro/liters from tube 10-2, placing them in the agora plate 10-3 & spreading it. Same procedure was done for the other three plates left. The 100micro/liters from the 10-4 tube were placed on the plate labeled 10-5 & the 10-6 100micro/liters were placed in the plate labeled 10-7. Same procedure done from 10-8 to 10-9 plate. Dilutions had to be a week in a rack in order to see results.
III. Results The smell of the Hay Infusion was not as acute as predicted however, the water looked foggy, as if it had accumulated a kind of white dirt. At glance, it had no apparent life at the top of the Hay Infusion. At each of the levels (top, middle, and bottom), microorganisms were found. A Peranema was found in the top level, it looked like a clear, fast-moving, micro-snake. It was very small and had a dark spot in the center of its body. Arcella was found in the top and middle niche; it was clear colored, long, and looked like a micro-sized snake. It could not be precisely measured, however it was fairly big in size. In the middle niche an Euglena was found. It was long, clear, & small. In the bottom a Paramecium was found. It was round, clear, moved fast from side to side, and small as well. The serial dilution made for the agora plates have to be incubated for a week in order to see the results.
IV. Data and Observations