Frequently Asked Questions about the QTest Photmeter
Can anyone use the QTest Photometer?
Yes! The photometer is designed to be user-friendly, even for those without a scientific background. If you follow the user manual and read through this FAQ, you’ll be able to use it with ease. If you have any questions, feel free to email us — we’re always happy to help.
What is the QTest Photometer?
The QTest Photometer is a small analytical device that measures how much of a specific substance (like MDMA, LSD, or psilocybin and many more to come) is in your sample.
What should I do before measuring a sample?
First, switch on the photometer and let the LED warm up for 5–10 minutes. After that, you must always perform a blank measurement to calibrate the device. If you're testing multiple samples of the same substance and the photometer stays on, you don’t need to blank it again between each measurement. However, every time you turn the photometer off and on again, you must redo the blank. You can keep your blank cuvette nearby and re-blank before each sample if you want to be extra careful.
What is a "blank," and why is it so important?
A blank is the detection solution without any sample in it. It tells the photometer what the baseline “zero” looks like. The detection solution itself has some color, and if you don’t blank properly, the photometer might mistake that background color for a positive result — giving you a false positive. That’s why blanking is essential for accurate readings. Always use a blank from the same QTest (MDMA, LSD, Psilocybin, etc.) that you’re going to use for your samples.
Can I reuse the cuvettes (the small plastic tubes)?
You can, but with caution. The reagents in the detection solution may stain or damage the cuvettes over time since, especially if they’re not cleaned immediately and the detection solution may contain acids that can damage them. If you decide to reuse them, rinse and dry them thoroughly as soon as you're done with the reading. Make sure they’re completely clear and show no traces of color, as leftover stains can interfere with your results. For beginners, we recommend using fresh cuvettes for each sample until you feel confident in your technique. If you are going to reuse them best yould be to use glass cuvettes.
Can I reuse the blank solution when using the Psilocybin Bulk Kit?
Yes, you can reuse the blank prepared during the Psilocybin Bulk Kit procedure, as long as it is stored correctly. After performing the blank measurement, pour any leftover solution into a clean glass container (not plastic), seal it tightly, and store it in the refrigerator, protected from light. Under these conditions, the blank can be reused for up to one month, we do not recommned to exeed this timing.
However, over time, the blank may slightly change color, especially after several days. This change can cause small variations in your results, typically around 1–3%.
If the blank becomes darker than it was originally, the photometer will treat this darker color as the new baseline (“zero”). When you later measure a real sample using a fresher and slightly lighter detection solution, the photometer may interpret the smaller difference between blank and sample as if the sample contains less active compound than it actually does. This results in a mild false negative, meaning your measurement may underestimate the true concentration. Whether this matters depends on how precise you want to be.
Can I return used blank solution to the original Bulk Kit reagent bottle?
No — never return any used solution to the original bottle from the Bulk Kit. Once the blank has been in contact with air or equipment, it may carry contaminants or traces of active compounds, which can spoil the rest of the reagent and compromise future tests. Always store reused blank solutions separately in a clean, labeled glass container. Keeping your reagents uncontaminated is key for getting reliable and consistent results.
Can I repeat or reset the blank measurement?
Yes! You can perform a blank measurement as many times as you like. Just insert the blank cuvette again and press the “zero” or “blank” button on the device.
When I turn on the photometer, I see some numbers on the screen — what do they mean?
Don’t worry — those numbers are completely normal. When you turn on the photometer, the little LED light inside starts shining, and the device begins to "look" through the air using light. That number you see is just the absorbance of nothing — basically, the device is seeing how much light is passing through the empty space.
Once you insert the blank cuvette (the one with clean detection liquid but no substance) and press the “blank” button, the photometer sets this as the true zero — from that point on, it knows how to compare the real samples. So, you don’t have to do anything with the number at the beginning. It’s just the machine warming up and checking its vision.
Why do the numbers sometimes fluctuate when reading a sample?
After inserting your sample and starting the measurement, you might notice that the numbers on the screen fluctuate slightly — for example, shifting between values like 14.59 → 14.63 → 14.57 before stabilizing. This behavior is normal and expected.
The photometer measures how much light is being absorbed in real time, and small environmental or handling factors can briefly affect the reading. These may include:
- Slight vibrations from the surface the device is on
- Temperature changes in the cuvette or surroundings
- Ambient light entering the chamber (if the lid is not fully closed)
- Misaligned or dirty cuvettes
- Touching the cuvette holder while the device is reading
What does the triangle on the cuvette mean, and why is orientation important?
Each cuvette has a small triangle marking — this triangle must point toward you and be aligned parallel to the photometer screen when inserted. This is important because the cuvettes are not perfectly symmetrical — the light path must go through the correct flat sides for accurate results. Misalignment can lead to errors in absorbance readings.
Can I test multiple samples with the same QTest reagents?
Yes, you can. Just make sure to use a clean cuvette for each sample and follow the same steps: blanking if needed, inserting the sample, and recording the result. This way, you can run multiple tests in a row without restarting the device.
Can I test both MDMA and LSD with the same photometer?
Yes! The photometer works with MDMA, LSD and Psilocybin QTes. However, each test requires its own specific detection solution and blank, so: test one substance at a time, perform the blank for each substance, and do not mix detection solutions or blanks across different QTests. We recommend finishing all measurements for one substance before starting with the next.
Is the QTest Photometer open source?
Yes! The QTest Photometer is open source, which means you can download the software and modify it to suit your needs. If you're tech-savvy, you can reprogram it, connect it to other tools, or even integrate it into your own systems.
Why will I get better results with more practice?
Because using the QTest Photometer is not just about following steps — it’s a hands-on learning process. These methods are built to be robust and reliable, so small variations (like slight differences in pipetting or timing) won’t ruin your results. But over time, you’ll start to notice patterns and build confidence in your technique.
Just like in any scientific experiment, precision comes from a combination of practice, attention, and curiosity. The more tests you perform, the more naturally you’ll recognize clean sample preparation, stable readings, and how to interpret your data accurately. It becomes a skill — and like any skill, it improves with experience and care.
And remember, you’re not doing this alone. We’re here to help. If you ever have doubts, want a second opinion, or simply want to share your progress, feel free to email us. You’re also warmly invited to join our Signal Photometer Community Chat, where users share insights, solve issues together, and grow as a community.
Where can I find calibration data or programming resources?
All calibration curves, data, and technical documentation can be found on our website: https://www.miraculix-lab.de/en/faq-photometer. There, you’ll also find links to join our Signal group for support and troubleshooting with other users.
Haven't found the answer you’re looking for?
Click here to find more FAQs or contact us via info@miraculix-lab.com or on Signal at +1 (509) 870-7678
We’ve also created a step-by-step guide for you. This guide is designed not only to help you follow the protocol, but also to provide you with valuable knowledge. Our goal is to ensure that you not only know how to use the QTest Photometer, but also understand the scientific reasoning behind each step: Step-by-Step-Guide Step-by-Step-Guide
