Ágar e Agarose

Agar (pronounced /ˈɑːɡər/, "ah-gər") or agar-agar (/ˈɑːɡərˈɑːɡər/, "ah-gər-ah-gər") is a gelatinous substance, obtained from algae and discovered in 1658 by Minora Tanzaemon in Japan, where it is called Kanten, and is used traditionally in some confectionaries.

Agar is derived from the polysaccharide agarose, which forms the supporting structure in the cell walls of certain species of algae, and which is released on boiling. These algae are known as agarophytes and belong to the Rhodophyta (red algae) phylum .^[1][2] Agar is actually the resulting mixture of two components: the linear polysaccharide agarose, and a heterogeneous mixture of smaller molecules called agaropectin.^[3]

Throughout history into modern times, agar has been chiefly used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture medium for microbiological work. Agar (agar-agar) can be used as a laxative, an appetite suppressant, vegetarian gelatinsubstitute, a thickener for soups, in fruit preserves, ice cream, and other desserts, as a clarifying agent in brewing, and for sizing paper and fabrics.^[4]

An agarose is a polysaccharide polymer material, generally extracted from seaweed. Agarose is a linear polymer made up of the repeating unit of agarobiose, which is a disaccharide made up of D-galactose and 3,6-anhydro-L-galactopyranose.^[1] Agarose is one of the two principal components ofagar, and is purified from agar by removing agar's other component, agaropectin.^[2]

Agarose is frequently used in molecular biology for the separation of large molecules, especially DNA, by electrophoresis. Slabs of agarose gels (usually 0.7 - 2%) for electrophoresis are readily prepared by pouring the warm, liquid solution into a mold. A wide range of different agaroses, of varying molecular weights and properties are commercially available for this purpose.

Romanowsky type stains

Any stain containing methylene blue and/or its products of oxidation (azure B), and a halogenated fluorescein dye, usually eosin B or Y.

The western blot = immunoblot

The western blot (sometimes called the protein immunoblot) is a widely accepted analytical technique used to detect specific proteins in the given sample of tissue homogenate or extract.

It uses gel electrophoresis to separate native proteins by 3-D structure or denatured proteins by the length of the polypeptide. The proteins are then transferred to a membrane (typically nitrocellulose or PVDF), where they are stained with antibodies specific to the target protein.

There are now many reagent companies that specialize in providing antibodies (both monoclonal and polyclonal antibodies) against tens of thousands of different proteins.
Commercial antibodies can be expensive, although the unbound antibody can be reused between experiments.
This method is used in the fields of molecular biology, biochemistry, immunogenetics and other molecular biology disciplines.