Why are my results so inconsistent?

Any biological parameter that is measured in your strain needs a defined physiological or ‘normal’ range. The difficulty is, every test is also affected by pre-analytical variables like sampling technique and timing of collection, conditions of the grow environment, nutrient and amendment selection, etc. Plant material such as cannabis flower can vary a surprising amount, with a general normal variation between samples 4-7% within the same loci, and as much as 12-15% across the plant.

All these variables have to be taken into account while defining “normal” values. Additionally, since samples are not typically collected from their lots by a representative of the laboratory, it is difficult to be certain about the homogeneity of health and conditions of the harvests from which they came. Because it is crucial that you receive accurate data about the nature of your harvested lot, it is crucial that you do all that you can to ensure the samples you send are truly representative of that lot for the purpose of obtaining data from which your strain’s “normal” ranges can be established. As a greater number of samples of each strain are tested, reference limits arise between which the normal range (reference interval) emerges.

The greater the percentage of a lot is tested, the more refined this range becomes. The value comes when a sample is tested that falls unacceptably outside of the reference interval for that strain, and it is recognized for further analysis to decide if that sample’s result is erroneous lab data, non-representative sample of the lot, a shift in genetics, a single plant pathology issue, etc.

Being sure your results are accurate requires a strong communicative relationship with your laboratory. Best practices on both sides of the testing bench rely on excellent communication between the farmer and the scientist. Cherrypicking your samples only acts to convolute an already complicated reality, and causes confusion and mistrust between your business and your buyers.