One of the key components of any analytical method is the detector. In the case of ATP testing, that detector is a photomultiplier tube located inside our luminometer which is tasked with the important role of measuring the amount of light produced from the reaction between ATP and the Luminase enzyme. And while our luminometers are designed for field-use and built to withstand the harsh conditions that can be encountered on the road and in industrial settings, it is still a light detector so it’s important to keep the unit clean to ensure accurate readings and protect it against damage.
If you open the lid of the luminometer, you’ll see the small chamber where the assay tube sits. Below that is another chamber where the Photomultiplier tube is housed, ready to measure the light output emitted from the solution in the assay tube. When the lid is closed, the assay tube is pushed down into that chamber and the unit is sealed to prevent light leakage from the environment. There are several things however that can affect these seals, both under the lid and in the bottom chamber: assay tubes may have been forgotten in the luminometer while it’s being transported from site to site, samples could have spilled into the chamber or the lid may have been left open on a windy day allowing dust and particulate to settle in. This can result in potential light leakage and damage to the photomultiplier tube if it happens often without regular cleanings.
So how do you clean the PhotonMaster luminometer effectively without causing more damage?
It’s important not to use an alcohol-based solution or cotton swabs – alcohol-based solutions can damage the unit while cotton swabs can leave behind small fibers that build up in the chamber. Always use the foam swabs and water-based cleaning solution provided by LuminUltra and never insert any sharp objects into the chamber. Routine cleanings should be performed at least once per year, and anytime reagent is spilled inside the chamber or an assay tube was forgotten in the luminometer while it was being transported.
To perform the cleaning, follow these 6 simple steps:
Note: If fluid has spilled into the chamber, first allow the unit to sit upside down in a clean location away from direct sunlight.
- Remove the rubber gasket from around the chamber.
- Lay the unit on its side with the lid open.
- Apply 6-8 drops of the recommended cleaning solution to the foam swab and allow it to be absorbed.
- Slowly insert the swab into the chamber until it stops and turn the swab 6X clockwise and 6X counter clockwise ensuring the whole length of the chamber is cleaned.
- Use a new swab to dry the chamber and then visually inspect to ensure all debris has been removed.
Note: Luminase is extremely sticky and may require several cleanings to remove completely if it’s spilled in the chamber. Simply repeat this process until it’s removed.
By following these simple steps, your PhotonMaster luminometer can be cleaned safely to reduce the risk of damage to the Photomultiplier tube and ensure no light leakage when you’re running your analyses. If you have any questions or would like more information, our Technical Support team is always happy to help.