Also found in: Dictionary, Thesaurus, Medical, Financial, Acronyms, Wikipedia.


see formaldehydeformaldehyde
, HCHO, the simplest aldehyde. It melts at −92°C;, boils at −21°C;, and is soluble in water, alcohol, and ether; at STP, it is a flammable, poisonous, colorless gas with a suffocating odor.
..... Click the link for more information.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(also paraform), a mixture of formaldehyde polymerization products, called polyoxymethylenes, of the general formula (—CH2O—)n where n is any integer from eight to 100. Paraformaldehyde is a white, crystalline substance with a melting range between 105° and 150°C. It is obtained by evaporating concentrated, aqueous solutions of formaldehyde in vacuo. Paraformaldehyde is a convenient source of formaldehyde.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


(organic chemistry)
(HCHO)n Polymer of formaldehyde where n is greater than 6; white, alkali-soluble solid, insoluble in alcohol, ether, and water; used as a disinfectant, fumigant, and fungicide, and to make resins.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
We fixed whole embryos or PND1 mice for 24 hr at 4[degrees]C in 4% paraformaldehyde, pH 7.4, followed by 20% sucrose for 24 hr at 4[degrees]C.
Bis(3-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (BA-a) or Bisphenol-a as a standard benzoxazine monomer, paraformaldehyde (99%), Tetrahydrofuran (THF), aniline (99%) and 3aminopropyltrimethoxysilane (98%) were supplied from Sigma Aldrich Co.
In this stage, 4-t-butyl-2-(N-piperdinomethyl)cyclohexanone was produced from 4- t-butyl-cyclohexanone, piperidine and paraformaldehyde according to reference one.
Vaginas were removed and fixed in paraformaldehyde and processed for subsequent histological examination.
The cells were cultured on coverslips for 24 hours and at the end of the drug treatment fixed in 4% paraformaldehyde in phosphate buffer (pH 7.4) at room temperature for 15 min and then incubated with a permeabilizing solution (0.1% Triton X-100) for 10 min at 4[degrees]C.
The thyroid tissue was fixed with 4% paraformaldehyde and embedded in paraffin.
Teratocytes were immediately fixed in 3% paraformaldehyde in HEPES wash buffer for 10 min in a gentle vacuum and 2hrs at room temperature for fluorescent studies.
Surgical specimens were immersed in 4% paraformaldehyde, decalcified with EDTA, and embedded in paraffin.
For this purpose, hydroxyl-containing benzoxazine monomer was first prepared by conventional ring-forming reaction of phenol with paraformaldehyde in the presence of 6-amino-l-hexanol.
On PD 15, we intracardially perfused the rats with phosphate-buffered saline (PBS) containing 4 percent paraformaldehyde. We removed the brains and postfixed them in 4 percent paraformaldehyde for 24 h, followed by incubation in cryoprotectant.
Subsequently, 4% paraformaldehyde (4[degrees]C; Sigma, USA) was added to each well (300 [micro]L/well) for 15 minutes, and glass coverslips were rinsed three times with PBS solution (1% triton X-100, pH 7.4) for 5 minutes each.