Is a peach/orange color sample a negative or a positive result for youPCR assay?

If your sample is not a definite yellow or pink the test is inconclusive. You should dilute your DNA 1:10 and rerun that assay.

If your sample does not change all the way to yellow or remain a definite pink then there has been some interference in the reaction and result is unknown. You should take 2µL of your solution A with DNA in it, and add it to 18µL of unused solution A. Then use the diluted DNA to rerun the assay in question. Below is an example of an orange/peach sample that should be considered inconclusive. #7 should be diluted and re-run with the youPCR assay.

There could be a few reasons for this to occur. There could be too much DNA present, say if you were collecting from a mature leaf. There also could be trace amounts of foliar sprays on the leaf. The color change is a result of a change in pH of the solution. So diluting the contaminate spray or the concentrated DNA helps increase reaction efficiency.

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