Calcium ions are important second messengers in cells. They are involved in muscle contraction, nerve signal transmission, immune cell activation, hormone secretion etc. Fluorescent calcium indicators selectively bind to calcium ions and show a spectral response upon binding Ca2+, i.e. fluorescence intensity or wavelength are changing. This shift of fluorescence wavelength and change of intensity upon calcium chelation can be monitored using fluorescence microscopy. Fura-2, Fluo-3, Rhod-2 and Indo-1 (as cell-impermeable salts or cell-permeable AM esters) as well as their low-affinity derivatives Fura-2FF, Fluo-3FF, Indo-1FF which are particularly useful for certain applications

Fluorescence-linked detection is best used for high-resolution studies. In addition, some fluorochromes have emission spectra that do not overlap, so two fluorochromes can be observed on the same sample. This allows the study of two different antigens in the same specimen even when they have identical subcellular distributions. Flurorescein, rhodamine, and Texas Red are the most commonly used fluorochromes. Fluorescein emits a yellow-green light that is easily detected, but it is prone to rapid photobleaching. Rhodamine emits a red color and is not as prone to fading as fluorescein, but the rhodamine conjugates are more hydrophobic and therefore yield higher

Dyes that emit light when exposed to light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags. They are used as markers in biochemistry and immunology. Fluorescent dye - a yellow dye that is visible even when highly diluted; used as an absorption indicator when silver nitrate solution is added to sodium chloride in order to precipitate silver chloride (turns pink when no chloride ions are left in solution and negative fluorescein ions are then absorbedophors or luminescence.

Fluorescent labels have long been useful to biomedical researchers interested in studying the structure and function of proteins and how they interact with their environment. Researchers 'label' proteins by attaching a fluorophore, or fluorescent molecule, to the protein that they are interested in studying. In the past, the most commonly used fluorescent label was Green Fluorescent Protein (GFP), which comes from jellyfish. Labels also find many applications in fluorescence spectroscopy

A fluorophore, in analogy to a chromophore, is a component of a molecule which causes a molecule to be fluorescent. It is a functional group in a molecule which will absorb energy of a specific wavelength and re-emit energy at a different (but equally specific) wavelength. The amount and wavelength of the emitted energy depend on both the fluorophore and the chemical environment of the fluorophore. This technology has particular importance in the field of biochemistry and protein studies, eg. in immunofluorescence and immunohistochemistry.

A group of heterocyclic compounds that are based on the 4-(2-amino-3,4-dihydro-4-oxopteridin-6-ylmethylamino)benzoic acid (pteroic acid) and conjugated with one or more L-glutamate units. Folate derivatives are important in DNA synthesis and erythrocyte formation. Folate deficiency leads to anemia.

Galacto-oligosaccharides (GOS) belong, together with fructo-oligosaccharides (FOS) and inulin, to the group of non-digestible carbohydrates (NDO). NDO may be regarded as soluble dietary fibres as regards their compliance with a generally accepted definition of dietary fibre including both biochemical and nutritional/physiological criteria. GOS, along with other soluble fibres, is a fermentable substrate for anaerobic bacteria in the large intestines. The main fermentation products are the short chain fatty acids acetate, propionate and butyrate. Short chain fatty acids reduce the colonic pH, which results in precipitation of bile acids and inhibition of the formation of secondary bile acids. High concentrations of secondary bile acids have been associated with an increased colon cancer risk.

Carbohydrates (literally hydrates of carbon ) are chemical compounds that act as the primary biological means of storing or consuming energy They are compound of carbon, hydrogen and oxygen, the latter two usually in the proportions of water (CH2O)n. They are classified into mono-, di-, tri-, poly- and heterosaccharides. Carbohydrates in food are an important and immediate source of energy for the body; 1 gram of carbohydrate yields 3.75 calories (16 kilojoules). They are present, at least in small quantities, in most foods, but the chief sources are the sugars and starches of plants. Herbivores are able to utilize the insoluble polysaccharides (crude fiber) because of bacterial conversion to volatile fatty acids by fermentation in the rumen and cecum.Carbohydrates may be stored in the body as glycogen for future use. If they are eaten in excessive amounts they are converted to and stored as fat.

Many different chemical moieties may be introduced into the cyclodextrin molecule by reaction with hydroxyl groups lining the upper and lower ridges of the toroid.For example methyl,hydroxy propyl,carboxymethyl and acetyl Since each cyclodextrin hydroxyl group differiIn its chemical reactivity the reaction produces an amorphous mixture of thousands of positional and optical isomers.The amorphous property contribute to the greatly enhanced solubility.The pharmaceutical usefulness of natural, crystalline cyclodextrins can be improved by chemical conversions into water-soluble, amorphous mixtures of their derivatives.

In situ hybridization technique utilizes the fact that DNA and RNA will undergo hydrogen bonding to complimentary sequences of DNA or RNA. By labeling sequences of DNA or RNA of sufficient length (approximately 50-300 base pairs), selective probes can be made to detect particular sequences of DNA or RNA. The application of these probes to tissue sections allows DNA or RNA to be localized within tissue regions and cell types. In situ hybridization is a powerful technique and unique in the way that it allows one to study the macroscopic distribution and cellular localization of DNA and RNA sequences in a heterogeneous cell population.

Inosine is a nucleoside involved in the formation of purines and a compound with possible roles in energy metabolism. Inosine is not an amino acid but is classified as a nucleoside, one of the basic compounds comprising cells. It is a precursor to adenosine, an important energy molecule, and plays many supportive roles in the body, including releasing insulin, facilitating the use of carbohydrate by the heart, and, potentially, participating in oxygen metabolism and protein synthesis.It is associated with the development of purines, nonprotein nitrogen compounds that have important roles in energy metabolism. It has been suggested that inosine may improve ATP (Adenosine Tri-Phosphate) production in the muscle and thus be of value to strength athletes. It is also thought to enhance oxygen delivery to the muscles which would benefit endurance athletes.