Objective:

The goal of this lab was to determine the texture of our soil and identify the Genus species of our tree.  Additionally, we began the DNA extraction process for our soil samples.

Procedure:

Determining Soil Texture Cont.

1. Use a ruler to measure the % sand, silt, and clay. This procedure works best by taking a clear picture of the tube and zooming in on the sedimentation lines.
2. How can you determine the % of each type of soil particle?
3. Use the USDA triangle and Soil Type Calculator to determine the texture of your soil.
4. Record your soil type

Silica Bead DNA Extraction

1. weigh 1 gram of soil and 1 gram of silica beads, transfer into an autoclaved mortar and pestle an grind finely for about 5 minutes
2. add 2mL of the DNA extraction buffer and 10 mg of powdered activated charcoal to the soil-glass mixture and mix it by pipetting several times
3. transfer the contents into a 2mL eppendorf tube
4. incubate the tube in a hot plate at 65C for 10 minutes.
5. centrifuge the tube at 12000g for 5 minutes
6. extract as much of the supernatant as possible and transfer it into a fresh eppendorf tube

Out of our group of three, we decided to use Holli’s soil. In this procedure different components we’re added to aid in the extraction process. For example, the silica beads were added to help break down the soil. Furthermore, the charcoal was added to further remove impurities from the mixture.

Data: 

I determined that my soil was 32% sand, 64% silt, and 4 % clay. Therefore I would classify the texture of my soil as Silt Loam.

We classified our tree as a Quercus Virginiana Live Oak because of its evergreen leaves. We also used inaturalist and the other tree ID website to help confirm our classification.

Observations:

Last week during lab I was able to find ciliates in my non-flooded plate. I attempted to culture the ciliates but had no luck in finding any this week when I observed the well plates. Although, I was able to observe what we believe to be flagellates in my culture.

Conclusion: 

I am continuously learning about trial and error in lab. This week our lab group had to re-do the DNA extraction procedure because it did not work out for us the first time. Luckily, the second time around we knew what to do and how to do it better than the first time.

Future Goals:

In the future I am excited to continue the DNA Extraction process. I also plan to begin writing my methods draft in order to keep the events of lab clear and organized.