Biomaterial Database

Polyethylene glycol embedding: a technique compatible with immunocytochemistry, enzyme histochemistry, histofluorescence and intracellular staining. 1983

K G Smithson, and B A MacVicar, and G I Hatton

A technique is described which permits rapid processing of neural tissue for light microscopic analysis of sections of 1-40 microns thickness. This technique was developed as an alternative to paraffin embedding. When compared to paraffin, polyethylene glycol (PEG) offers the following advantages: 10-15 degrees C lower embedding temperatures, net tissue shrinkage of less than 5% vs approximately 50% in paraffin, and approximately one-half the embedding time. Tissue orientation during embedding and sectioning is particularly easy to control, e.g. 500 microns brain slices can be routinely flat-embedded and sectioned at 5 microns to form excellent ribbons. Since PEG is water-soluble, tissue may be dehydrated with a series of aqueous PEG solutions; the embedding matrix is easily removed by washing with a variety of aqueous buffers. These procedures allow subsequent electron microscopic analysis of material with generally well preserved ultrastructure. However, PEG is hygroscopic, thus tissue blocks become soft and difficult to section in high (greater than 90%) relative humidity. PEG was found to be compatible with intracellular staining with Lucifer yellow, horseradish peroxidase enzyme histochemistry, aqueous histofluorescence and immunocytochemical demonstration of neuronal peptides and glial fibrillary acidic protein.

UI	MeSH Term	Description	Entries
D007158	Immunologic Techniques	Techniques used to demonstrate or measure an immune response, and to identify or measure antigens using antibodies.	Antibody Dissociation,Immunologic Technic,Immunologic Technics,Immunologic Technique,Immunological Technics,Immunological Techniques,Technic, Immunologic,Technics, Immunologic,Technique, Immunologic,Techniques, Immunologic,Antibody Dissociations,Dissociation, Antibody,Dissociations, Antibody,Immunological Technic,Immunological Technique,Technic, Immunological,Technics, Immunological,Technique, Immunological,Techniques, Immunological
D007267	Injections	Introduction of substances into the body using a needle and syringe.	Injectables,Injectable,Injection
D007425	Intracellular Membranes	Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.	Membranes, Intracellular,Intracellular Membrane,Membrane, Intracellular
D007546	Isoquinolines	A group of compounds with the heterocyclic ring structure of benzo(c)pyridine. The ring structure is characteristic of the group of opium alkaloids such as papaverine. (From Stedman, 25th ed)
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010640	Phenothiazines	Compounds containing dibenzo-1,4-thiazine. Some of them are neuroactive.
D011092	Polyethylene Glycols	Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.	Macrogols,Polyoxyethylenes,Carbowax,Macrogol,Polyethylene Glycol,Polyethylene Oxide,Polyethyleneoxide,Polyglycol,Glycol, Polyethylene,Glycols, Polyethylene,Oxide, Polyethylene,Oxides, Polyethylene,Polyethylene Oxides,Polyethyleneoxides,Polyglycols,Polyoxyethylene
D004798	Enzymes	Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.	Biocatalyst,Enzyme,Biocatalysts
D005453	Fluorescence	The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry