If you manage a water system – whether it‘s wastewater, drinking water oder water used for industrial purposes – a luminometer can make your job a lot easier. Read on to find out more on how a luminometer works and about the detection technology inside the device.

Luminometers Provide Easily Interpreted Answers to Molecular Questions

Luminometers have been used in laboratories around the world for many decades, helping to provide easily interpreted answers to molecular questions. The detection technology the devices use is proven and reliable. When it comes to water, luminometers let you quickly and easily analyze samples while working in the field.

Luminometers are used to measure the chemical marker ATP (short for adenosine triphosphate). ATP is a compound found in each and every type of microbial, animal and plant cells. With the help of a luminometer and the advanced detection technology inside, you can determine the size of the microbial population that is present in any given sample based on how much light is produced when adenosine triphosphate reacts with the enzyme luciferase.

Luciferase is the same enzyme that makes the tails of fireflies grow. It is also widely used for microscopy, in biotechnology and as reporter genes, for many of the same applications as fluorescent proteins. Luciferases do not require an external light source, but addition of luciferin, the consumable substrate.

In the so-called “luciferase reaction“, light is emitted when luciferase acts on the appropriate luciferin substrate. The amount of light generated is proportional to how much adenosine triphosphate is present, which instantly shows the level of biological contamination. The photon emission can be detected by a light sensitive apparatus which uses an advanced optical detection technology, e.g. a luminometer or modified optical microscopes. This allows observation of biological processes.

Key Components of the Luminometer

One of the crucial parts of a luminometer is the detection technology. In modern equipment, a photo multiplier tube (or PMT) is used as a detector. A photo multiplier tube is a highly sensitive vacuum phototube which is able to detect a range of types of light. The other key part is a light-tight chamber that is needed to read the signal. In general, two different types of photo multiplier tubes are getting used – photon-counting PMTs and current mode PMTs. The former are widely accepted as being the most sensitive devices for detecting luminescence.

This kind of detection technology was used during the Apollo 11 mission when the astronauts tried to verify the Big Bang Theory. They put an array of five mirrors on the surface of the moon to let scientists track if the pale terrestrial satellite was getting further away from the earth or closer. The same detection technology is used for countless other scientific applications. This includes, among others, devices for blood analysis in clinical laboratories.