Bio- and Chemiluminescence technologies are employed in many areas: Clinical diagnostics, Fundamental research, Drug development, Process measurement, Environmental measurement and many more. A few of the most popular applications are described below:
 
Reporter Gene Assays
Reporter genes are widely used to study gene expression and regulation mechanisms in living cells. Since not all expressed enzymes are easily detectable, reporter genes were introduced into cellular DNA to investigate gene function by means of a measurable property, luminescence.These reporter genes are for example: firefly luciferase, beta-galactosidase, alkaline phophatase beta-glucuronidase, beta-glucosidase. By far the most popular reporter is the firefly luciferase from the american firefly (Photinus pyralis). The high sensitivity, easy handling, short process time and a high quantum yield of the bioluminescence reaction make this method to the "method of choice" to understand gene regulation. Typical commercial assay kits are optimized for extended half life time of more than five minutes.

 

ATP Assays
ATP assays, based on the catalytic reactions of firefly luciferase (from the american firefly Photinus Pyralis) resulting in light emission, has become an important analytical tool in science and industry. The presence of ATP in all living cells is the base for various applications, which has been described in numerous publications during the last years.

 

* Assays for Hygiene and Sterility Monitoring (free and microbial ATP)
* Determination of Enzymes and Metabolites in ATP Linked Reactions
* Antibiotic Susceptibility Testing
* Tumor Chemosensitivity Studies
* Cytotoxicity Testing
* Cell Proliferation Assays
* Apoptosis Assays
* Testing for Urinary Tract Infection
* and many others

Mycoplasma Infection of Cell Cultures
Mycoplasma contamination of cell cultures occurs frequently, but often remains undetected. This infection is not without serious consequence as virtually every cellular process can be altered by the infection. In the worst scenario, the contamination leads to diminished cell growth and eventually to the loss of cultures. Mycoplasmas from human, bovine and porcine sources are the most prevalent groups with Acholeplasma laidlawii, Mycoplasma arginini, M. fermentans, M. hominis, M. hyorhinis, and M. orale being the most common isolates. (source: http://www.dsmz.de/mutz/mutzmyco.htm) The MycoAlert® Assay is a luminescent assay which detects mycoplasma contamination quickly and reliably, while being very easy to perform.

 
Chemiluminescence Immunoassay (CLIA) 
The use of chemiluminescence labels in quantitative detection of ligand-binding assays (LIA- Luminescence Immunoassay), has become more and more popular in clinical applications such as the determination of specific antigens, antibodies, drugs or hormones in blood or other body fluids. They replace the less reliable and inconvenient to handle isotopic labels. The popularity of the LIA application continues to grow due to the exquisite detection sensitivity of a few nano- or picomols per liter, which is necessary in most clinical applications along with excellent reproducibility. The low native background combined with a large dynamic range of the instrumentation is the prerequisite to cover a broad linear range of analyte concentrations.

 
Two types of Luminescence Immunoassays can be distinguished:
A: Direct labels like acridiniumesters or isoluminol, which emits the lights directly after triggering the assay conditions (addition of H2O2 and pH adjustment).
B: Enzyme linked labels like the alkaline phosphatase (AP) or the horseradish peroxidase (HRP), which initiate multiple chemiluminescence reactions in the later reaction, due to the enzymes turnover rate. This results in an amplified signal.

Infectious Disease
Chemiluminescence assays are gaining importance in the diagnosis of infectious diseases. They are used widely in detection of sexually transmitted disease, such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC), as well as Human Immunodeficincy Virus (HIV), Hepatitis B Virus (HBV), Hepatitis C Virus ( HCV), Human Papilloma Virus (HPV) strains causing cervical cancer, Mycobacterium tuberculosis and others.

Reactive Oxygen Species (ROS)
Cellular metabolism is characterized by oxidative and reductive processes. As a by-product of these cellular reactions free radicals are formed, which may further react with various cellular components (e.g. Lipids, DNA,..). The most reactive oxygen radicals are called reactive oxygen species (ROS). They may express a very weak native chemiluminescent signal (e.g. Singulett-Oxygen 1O2) or can be detected by sensitized chemiluminescent reactions, enhanced by Luminol, Lucigenin or other substances. Whereas in the healthy organism redox regulation is balanced, alterations in the oxidative homeostasis (=balanced concentration) are used to study diseases.

Phagocyte Respiratory Burst
Specific cells of the immune system, polymorphonuclear leukocytes (PMNL) or phagocytes, are one of the most important types of effector cells of immune defense against infection and inflammation. During their action against microbes or toxins they bind these factors on specific receptors (opsonin receptor), absorb them by phagozytoses and finally kill or destroy them through the action of reactive oxygen species. A reaction called respiratory burst.
Main applications are:
* Study pathogenesis of various inflammatory processes (e.g. rheumatoid arthritis, arteriosclerosis) * Pre and postoperative studies of cancer patients
* Screening of new drugs
* Study allergic processes
Isolated phagozytes or whole blood are used to determine the degree of activation or depression of this response by means of stimulating agents which imitates the action of microbes or toxins (opsonized Zymosan, PMA (phorbol-myristate-phenylalanin) or fMLP (formyl-methionyl-leucyl-phenyalanine). After addition of e.g. Luminol as an enhancer the mircoplates are placed in a temperature controlled luminometer (37°C) and the luminescent signal is monitored over a period of 60 minutes.

 

Endotoxin is believed to be the most important microbial trigger for sepsis. Sepsis is a syndrome characterized by an overwhelming response by the body to the presence of bacterial products in the blood. Sepsis may cause multiple organs in the body to fail and trigger the onset of both abnormal clotting and bleeding. Sepsis can also rapidly lead to organ failure and ultimately death. It can strike anyone but is most likely to develop in association with pneumonia, trauma, surgery, burns or conditions such as cancer and AIDS. The EAA™ Endotoxin Activity Assay is the only FDA approved rapid whole blood assay for detection of human endotoxemia.

 

Neuraminidase Inhibition
Influenza ("flu") is a viral diesease that affects birds and mammals. The two large glycoproteins hemagglutinin (HA) and neuraminidase (NA) are responsible for many pathogenic properties, such as host specificity, and resistance. NA is the major target for anti-flu agents. Recently, chemiluminescence assays for the assessment of neuraminidase activity (or neuraminidase inhibition) have become commercially available.