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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.
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(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.


(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.
References in periodicals archive ?
In method I, HeLa cells were fixed with 2% paraformaldehyde and permeabilized with saponin and the hybridization was performed in the presence of 5'-FITC- labeled antisense probe for intracellular detection of 18S rRNA.
Hydroxyl-containing benzoxazine monomer (Bz-OH) was synthesized in the usual manner through Mannich condensation reaction of phenol and 6-amino-1-hexanol, in the presence of paraformaldehyde (Scheme 1).
PMN were incubated with streptavidin-PE and PBMC were double labeled with streptavidin-PE and anti-CD3-PerCp during 30 min at 4[degrees]C, washed twice with PBS-EDTA and fixed with 1% paraformaldehyde in PBS.
9% saline) followed by immersion in 200 ml of fixative solution that contained 4 per cent paraformaldehyde in 0.
The serum from patient 1 exhibited a diffuse fluorescence pattern that was mainly localized to the nuclei of all cells in the cochlea on both paraformaldehyde (figure 3) and acetone (figure not included) preparations.
Sperm were fixed in 1 mL of 3% paraformaldehyde in PBS, for 24 hours minimum at 4[degrees]C.
After 20 h of incubation, the coverslips were rinsed extensively with PBS; cells were fixed with freshly prepared 4% paraformaldehyde in PBS for 15 min at room temperature and then rehydrated with PBS.
Sections: Ileum segments, approximately 1 cm long, were fixed in fresh 4% paraformaldehyde solution in PBS, pH 7.
It is thought that chemical catalyst paraformaldehyde, used by the company in its chemical blending processes, swamped a waste incinerator.
We considered vaporized hydrogen peroxide (VHP), chlorine dioxide and paraformaldehyde.
pipistrellus specimen fixed by immersion in 4% paraformaldehyde was provided by D.
Control and MK-801 groups with 6 or 24 h survival underwent either (1) transcardiac brain perfusion-fixation with 4% paraformaldehyde for H & E, TUNEL and CM1 antibody (to active caspase-3) staining, or (2) decapitation and rapid dissection and homogenization of neocortex for DNA gel electrophoresis, Western blot analysis of active caspase3 and activity of endogenous caspasc-3-like activity (DEVD-AFC cleavage assay).