Cannabinoid Potency Testing
MarPro is excited to offer affordable cannabinoid potency testing. For only $20 per sample we are able to test flower, liquids, and concentrates. Are you a commercial CBD operation that wants to check your percentage of THC and CBD, as well as percentage of water weight and amount of water activity for harvesting or just want an unofficial test before a state reported test? Or maybe you are a home grower interested in zeroing in their harvesting and curing, or just looking for bragging rights with their friends? Either way, we are happy to help.
How it works
We use a Purpl PRO to do our flower testing and a Tcheck to test liquids and concentrates.
To measure potency, the Purpl PRO utilizes near-infrared spectroscopy, which involves shining light on a sample and analyzing the light that is returned. In this part of the light spectrum (just beyond the red light human eyes can see), molecules react to specific regions of the light to generate a “molecular fingerprint” that can be correlated with concentration. In its development, the Purpl PRO was calibrated against HPLC measurements from multiple state-certified testing laboratories.
Testing for CBD using the Purpl PRO is similar to THC. Molecules of CBD absorb some amount of light at specific parts of the NIR, however it’s a different part of the NIR light than the THC measurement utilizes. If there is more CBD, it reflects more light. If there is less CBD, it absorbs more light.
When it comes to getting a great product, the curing process is the most important part of the cycle. To test for water activity and moisture, traditional lab testing methods typically require multiple days of allowing a sample to dry and cure, to allow the moisture to evaporate until the product reaches the critical parameter around <15% moisture. Thankfully, the Purpl PRO’s +H2O Pack delivers unlimited instant test results for both percentage moisture and water activity using NIRS, so you know what you have and if it’s truly ready to process, smoke or sell.
How accurate is the Purpl PRO? Overall, Purpl states a +/- 2% accuracy on THC and CBD for simplicity. Statistically, it is +/- 1.89% on THC and +/- 0.96% on CBD, determined by comparison with lab HPLC measurements.
Here is a link to a document detailing the scientific procedures and results of the Purpl PRO potency measurement validation.
Our testing results are not to be used for any official state reporting or as an official lab result as we are not a state certified laboratory. We are providing you with a general idea of your percentages. We do not report our results to anyone but the customer.
Sample prep/shipping and price
For flower testing we need about two grams of flower per sample/strain to be tested. For liquid testing we need 2ml of your tincture/concentrate. Most samples will be tested and results sent to you via email or text the same day they are received.
Two grams of your hemp product should be double bagged and clearly marked with strain name, phone number for text or email address/addresses for results, and any other identifiers you need for your samples including batch or plot numbers. We recommend a padded mailer sent registered mail, but a manila mailer will work too. If contents of package are needed "Hemp for testing" should suffice. Multiple samples/strains can be shipped in the same package.
Samples can be mailed to:
536 Pantops Center #334
Charlottesville, VA. 22911
Or for local (Charlottesville, Va. area) sample drop offs, sample bags and liquid vials are with dropbox. Label the same as shipping and leave in the MarPro Testing drop box located at
The Grow Depot
1147 River Rd. #1
Charlottesville, VA. 22901
While you are dropping off your sample don't forget to check out all the awesome products they have, including pot's, soil, lights and nutrients.
Samples are picked up daily and tested, with most results e-mailed/texted to you that day. Samples are destroyed after testing is complete.
The price is $20.00 per sample/strain
*At the moment we can only accept cash, Venmo and PayPal
If paying with cash, please include it with sample and make sure to contact us letting us know whether it was mail or drop off.
If paying with venmo, please include your name on packaging. We are MarPro LLC (@MarProTrim)
Please venmo when you drop off or send sample.
If paying with PayPal, please include your name on packaging. We are Marprotrimming@gmail.com. Please PayPal when you drop off sample or send sample.
Please contact us with any questions you might have via email, phone, or our "Contact Us" button.