The soil came from a cotton field in Clint, Texas (31.5996622 – 106.2469625). Around 9 am, we dug 9-12 inches down to get the soil; it was a clear and dry day so there was no contamination of rain or any other moisture.
Week 1 – After a couple of days of the soil and broth being in incubation, we then transferred them over to the four tubes, which included the 200 ul of SSM and CSM solution. You can kind of see some discoloration, but there was still a ton of incubation that needs to be done before confirming if it was positive or negative.
Week 2 – We repeated the steps with the CSM and SSM solution after a week of incubation. As shown in the picture, we still have some discoloration; thinking we might have pesticide-positive soil.
Week 3 – We repeated the steps with the CSM and SSM solution after a week of incubation. From what the picture shows, the yellow discoloration is still persistent.
Week 4 – We repeated the steps with the CSM and SSM solution after a week of incubation. The discoloration we had within the last few weeks has gone away, meaning we now believe that the soil sample is negative.
Week 5 – For the last week the tubes stayed clear, meaning our test results were negative.