Objective

• Analyze the soil texture of our soil samples
• Check our cultured ciliates
• Extract DNA from a soil sample and prepare it for purification (next lab)

Procedure

Finding and isolating ciliates:

1. Using a micropipette, place drops of water from the prepared 24-well plate onto a concavity slide
2. Under a dissecting microscope, search for any ciliates
3. Make sure to inform the TA/Professor if any are found

Determining soil texture:

This is the soil texture triangle diagram. It is used to determine soil type through the percentages of the soil composition.

Extracting and Preparing DNA from the Soil Sample:

1. Using a mortar and pestle, grind 1 g of the selected soil sample and 1 g of small silicon balls into fine powder
   1. My group selected Andrea’s soil sample
2. Add 1 mL of DNA extraction buffer, the solution to break open cells without destroying DNA
3. Add 10 mg of activated charcoal to get rid of the impurities in the sample
4. Mix the buffer, charcoal, and soil sample together
5. Transfer the contents into an eppendorf tube
6. Incubate the tube at 65°C for 10 minutes in a water bath
7. Centrifuge the tube, with the balancing concept in mind, at 12000g for 5 minutes at 4°C
8. Transfer the supernatant to the microfuge tube

Data

Leaf Characteristics and Pictures:

After analyzing and referencing the “Figure of Leaves” resource, I determined that the tree is a Chionanthus virginicus. The reasoning is because the leaf contains the following features:

• Elliptical leaf shape
• The edges of the leaf is smooth; entire
• Where the edge of the leaf meets the stem is acute
• The tip of the leaf is also considered acute in shape
• It is also palmately veined

Soil Texture:

The total measurement was 2.5 cm

Sand – 1.2 cm – 48%

Silt – 0.7 cm – 28%

Clay – 0.6 cm – 24%

After referencing the soil texture diagram, I determined that my soil sample was a sandy clay loam.

Ciliate Observations:

I did not observe any ciliates in my culture/24-well plate.

Unfortunately, I did not have the time to check my non-flooded plate.

Conclusion

It was unfortunate that I was not able to find any ciliates in my culture or non-flooded plate. With the new information I received, my soil sample being a sandy clay loam type, there may be a connection between the lack of ciliates and the soil type. It may be that the ciliates are unable to sufficiently survive in the soil composition that I had gathered for my soil sample.

Future Steps

We extracted our DNA this week, so I look forward to purifying them next lab. Dr. Adair will be bringing in the DNA purification kit, something I have never worked with/done before in my academic career.