after performing a PCR assay with the samples which yielded results with positive negative controls i designed a new PCR with different variables to identify the problem associated with the negative control showing a positive band.
It turned out that the Master mix for the PCR which i was using was contaminated with roundworm DNA
I then changed the Master mix and got results on the samples which turned out to be negative.
Next week i will add another step to the DNA extractions which means adding a homogenising step to help break up the roundworm eggs.