Aequorea victoria, also called the crystal jelly, is a bioluminescent jellyfish that is found off the west coast of North America. This species is thought to be synonymous with Aequorea aequorea by Osamu Shimomura who was the discoverer of green fluorescent protein. Originally the victoria species was supposed to designate the variant found in the Pacific and the aequorea designation for species found in the Atlantic and Mediterranean. The species name used in GFP purification was later disputed by Arai and Brinckmann-Voss (1980) decided to separate them on the basis of 40 specimens collected from around Vancouver Island. Osamu Shimomura notes that this species in general shows great variation and from 1961 to 1988 the Friday Harbor Laboratories of University of Washington around 1 million samples were collected and many times there were pronounced variations in the form of the jellyfish.

Aequorin is a photoprotein isolated from luminescent jellyfish (like various Aequorea species e.g. Aequorea victoria) and a variety of other marine organisms. It was originally isolated from the jellyfish by Osamu Shimomura. Aequorin is composed of two distinct units, the apoprotein apoaequorin, with an approximate molecular weight of 22 kDa, and the prosthetic group coelenterazine (molecular weight 472), a molecule belonging to the luciferin family.

Alkaline phosphatase (ALP) is a hydrolase enzyme responsible for removing phosphate groups from many types of molecules, including nucleotides, proteins, and alkaloids. The process of removing the phosphate group is called dephosphorylation. As the name suggests, alkaline phosphatases are most effective in an alkaline environment. In the context of life science laboratory work, ALP has become important as a labelling system. A variety of ALP substrates exist for colorimetric and luminescent readout. 

Short for adenosine triphosphate. ATP is an energy-carrying molecule found in the cells of all living things. It captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processes. ATP is a component needed for bioluminescence in fireflies. 

Background readings have various sources. A high background will reduce the sensitivity of an assay. Threrefore, a low background is desirable. Sources for background are electronic noise (which may increase with temperature), or memory effect of the detector or the sample container. In absorbance and fluorescence measurement, the light source constributes to background, which isn't the case in luminescence measurement due to the lack of a light source. In addition to hardware generated background, the reagent background is observed - in case of Berthold Detection Sytems`instruments, the reagent background is higher than instrument background. 

Bioluminescence, a form of chemiluminescence, is light that comes from living organisms. Bio means "living organism" and luminescence means "emission of light." Organisms that can produce light are called bioluminescent. Not to be confused with fluorescence or phosphorescence.

A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. The term "circadian", coined by Franz Halberg, comes from the Latin circa, "around", and diem or dies, "day", meaning literally "approximately one day." The formal study of biological temporal rhythms such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology. Another description of this topic is "biological clock". The regulatory elements involved can be studied conveniently using the luminescent reporter sytems.

Coelenterazine is found in radiolarians, ctenophores, cnidarians, squid, copepods, chaetognaths, fish and shrimp. It is the light-emitting molecule in the protein aequorin.

 

This describes the internal volume which is used up by tubings, dispensers, valves. Luminometers with automatic reagent injectors have a certain dead volume covering the path between the reagent bottle and the sample container. Before a luminometric measurement with reagent injection can start, this volume must be filled with reagent. The smaller the dead volume, the better, for economical reasons. Berthold Detection Systems instruments have the smallest dead volue in the industry, and their sytems offer backpumping of reagents if the user chooses to do it.

 

Small, single-celled organisms that live in the sea. Dinoflagellates are an important component of phytoplankton and a source of bioluminescence at the surface of the ocean.

 

The use of 1,2-dioxetane chemiluminescent substrates with alkaline phosphatase (AP) enzyme labels provides highly sensitive detection for numerous immunoassay and nucleic acid detection formats. Current applications include membrane-based detection of proteins and nucleic acids, immunoassays, microplate-based nucleic acid detection and, increasingly, array-based detection.

 

Dioxins are one of the most toxic man-made compounds known. They are persistent environmental pollutants and tend to accumulate in biota. Dioxin-like compounds such as PCBs and PCDFs show similar properties. This group of chemicals, also known as PHAHs, display a wide variety of toxic effects in mammals, birds, and fish. Among the toxic effects observed as a result of exposure to PHAHs are immunotoxicity, carcinogenicity, metabolic changes, and even death. Traditional analytical techniques for dioxins are too expensive and time consuming for food and feed screening. A Luciferase-based reporter gene bioassay offers a practical technology for monitoring for these compounds.

 

A reporter assay which employs to reporters, one for the signal, and one to normalize for experimental errors such as transfection efficiency. The most popular dual reporter assay is Dual Luciferase Assay, including firefly and renilla luciferase sytems.

 

 

Dynamic range is a term used frequently in numerous fields to describe the ratio between the smallest and largest possible values of a changeable quantity, such as in sound and light.

 

Lampyridae is a family in the beetle order Coleoptera, members of which are commonly called fireflies, lightning bugs or (ambiguously) "glow worms" due to their conspicuous nocturnal (or, more accurately, crepuscular) use of bioluminescence to attract mates or prey. Fireflies are capable of producing a "cold light" containing no ultraviolet or infrared rays, with a wavelength from 510 to 670 nanometers, pale reddish, yellowish or green in colour, with a lighting efficiency of up to 96%.

There are more than 2000 species of firefly found in temperate and tropical environments around the world. Many species can be found in marshes or in wet, wooded areas where their larvae have abundant sources of food.

 

Good Laboratory Practice (GLP) embodies a set of principles that provides a framework within which laboratory studies are planned, performed, monitored, recorded, reported and archived. These studies are undertaken to generate data by which the hazards and risks to users, consumers and third parties, including the environment, can be assessed for pharmaceuticals, agrochemicals, cosmetics, food and feed additives and contaminants, novel foods and biocides. GLP helps assure regulatory authorities that the data submitted are a true reflection of the results obtained during the study and can therefore be relied upon when making risk/safety assessments.

 

The enzyme horseradish peroxidase (HRP), found in horseradish, is used extensively in molecular biology applications primarily for its ability to amplify a weak signal and increase detectability of a target molecule. HRP is often used in conjugates (molecules that have been joined genetically or chemically) to determine the presence of a molecular target. For example, an antibody conjugated to HRP may be used to detect a small amount of a specific protein in a western blot. Here, the antibody provides the specificity to locate the protein of interest and the HRP enzyme, in the presence of a substrate, produces a detectable signal. Horseradish peroxidase is also commonly used in techniques such as ELISA and Immunohistochemistry. Horseradish peroxidase is ideal in many respects for these applications because it is smaller, more stable and less expensive than other popular alternatives such as alkaline phosphatase. It also has a high turnover rate that allows generation of strong signals in a relatively short time span.

 

Hygiene describes the absence of microorganisms. Bacteria and Fungi contain ATP which can be measured with the firefly luciferase detection. Many systems exist on the market which are based on this technology.

 

ISO 9000 is a family of standards for quality management systems. ISO 9000 is maintained by ISO, the International Organization for Standardization and is administered by accreditation and certification bodies. Berthold Detection Systems has been certified according to ISO 9000 since 1997.

 

In the context of luminescence measurement, this means the development of luminescence output over time.

 

The linear range is that range of input or output values for which an electronic amplifier produces an output signal that is a direct, linear function of the input signal. That is, the output can be represented by the equation: Output = Input × Gain. In luminometry, different detector designs exhibit different properties at the high end of the dynamic range: Analog detectors stay linear until the reach the saturation point. Photon counters lose linearity before they reach saturation. A simple photon counter will even show a hook effect beyond the saturation point: Very bright signals lead to low output which means that they can be mistaken for lower light signals. All Berthold Detection Systems Luminomerters ear equipped with "overload detection" which prevents this phenomenon.

 

Any of several organic compounds that, in the presence of the enzyme, luciferase, react with oxygen to produce bioluminescent light. Luciferins vary in chemical structure from organism to organism. The luciferin in fireflies, for example, is different from the luciferin in bioluminscent squid. Each type of luciferin is catalyzed by a specific luciferase.

 

Luciferase is a generic name for enzymes which generate bioluminescence in nature. The most famous one is firefly luciferase (EC 1.13.12.7) from the firefly Photinus pyralis. In luminescent reactions, light is produced by the oxidation of a luciferin. The rates of this reaction between luciferin and oxygen are extremely slow until they are catalyzed by luciferase, often mediated by the presence of calcium ions.

 

A Microtiter plate or microplate is a flat plate with multiple "wells" used as small test tubes. The microplate has become a standard tool in analytical research and clinical diagnostic testing laboratories. A very common usage is in the enzyme-linked immunosorbent assay (ELISA). A microtiter plate typically has 6, 24, 96, 384 or even 1536 sample wells arranged in a 2:3 rectangular matrix. In luminescence measurement, most applications are performed in white or black 96 well microplates.

 

In a photomultiplier or Phototube, a photocathode is a negatively charged electrode coated with a photosensitive compound. When this is struck by light, electrons are emitted due to the photoelectric effect.

 

Photomultiplier tubes (photomultipliers or PMTs for short) are extremely sensitive detectors of light in the ultraviolet, visible and near infrared. These detectors multiply the signal produced by incident light by as much as 108, from which single photons can be resolved. Photomultipliers are constructed from a glass vacuum tube which houses a photocathode, several dynodes, and an anode. Incident photons strike the photocathode material which is present as a thin deposit on the entry window of the device, with electrons being produced as a consequence of the photoelectric effect. These electrons are directed by the focusing electrode towards the electron multiplier, where electrons are multiplied by the process of secondary emission.

 

Photon Counting allows for very sensitive luminescence measurement, at a very high time resolution. 

 

Light-emitting organs found in many fish, squid and shrimp. Photophores are used to produce and store light. They vary in size and form, but often have lenses, reflecting layers and filters for directing light.

 

In the context of software for life science instruments, this describes the set of parameters used to perform measurement, evaluation and reporting of sample data.

 

In molecular biology, a reporter gene (often simply reporter) is a gene that researchers attach to another gene of interest in cell culture, animals or plants. Certain genes are chosen as reporters because the characteristics they confer on organisms expressing them are easily identified and measured, or because they are selectable markers. Reporter genes are generally used to determine whether the gene of interest has been taken up by or expressed in the cell or organism population. The most popular reporter gene is the luciferase enzyme of photinus pyralis (firefly).

 

Reactive oxygen species (ROS) include oxygen ions, free radicals, and peroxides, both inorganic and organic. They are generally very small molecules and are highly reactive due to the presence of unpaired valence shell electrons. ROSs form as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling. However, during times of environmental stress ROS levels can increase dramatically, which can result in significant damage to cell structures. This cumulates into a situation known as oxidative stress. They are also generated by exogenous sources such as ionizing radiation. A very sensitive and convenient way to measure ROS is the use of chemiluminescence. The molecules Luminol and Lucigenin, but also Pholasin are often employed to increase signal, as well as specifically detect certain molecules of the ROS group.

 

The sensitivity of a detection device, such as a luminometer, is the minimum magnitude of light signal required to produce an output signal (in case of our luminometers RLU or RLU/s) at a level which can be distiguished from background.

 

The value which is used to determine sensitivity of a luminometer.

 

The photocathode of a photomultiplier tube does not have the same sensitivity for all wavelenghts of light. For this reason, light of different wavelength will be detected with different sensivity. The maximum sensitivity. PMT used in a luminometer will typically have a peak sensivity of 25% conversion rate at 400-450 nm.

 

In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate(s).

 

Individual tumors of the same type can vary considerably in their response to chemotherapy. The luciferase-luciferin assay for ATP can be used as a very sensitive cytotoxicity assay. Consequently, a tumor chemosensitivity assay has been designed around this luminescence endpoint, and was tested extensively over the last ten years.

 

In the medical device, pharmaceutical and biotechnology manufacturing industries, validation refers to establishing documented evidence that a process or system, when operated within established parameters, can perform effectively and reproducibly to produce a medicinal product meeting its pre-determined specifications and quality attributes (from European Union Good Manufacturing Practices Guide, Annex 15). Regulatory bodies in the U.S., European Union, and Japan (amongst many others) require validation, causing it to become its own sub-industry supporting the pharmaceutical, biotechnology, and medical device industries. Berthold Detection Systems provides Validation devices (light sources such as the Luminescence TestPlate) as well as software and documention for the validation of the luminometers.

 

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