Formalin. See Formaldehyde

Fluorotrichloromethane, see Trichlorofluoromethane Fly-die, see Dichlorvos Fly fighter, see Dichlorvos FMC 5462, see a-Endosulfan, p-Endosulfan FMC 10242, see Carbofuran Foliclol, see Parathion Folidol, see Parathion Folidol E 605, see Parathion Folidol E E 605, see Parathion Folidol oil, see Parathion Forane, see 1,1,2-Trichlorotrifluoroethane Foredex 75, see 2,4-D Forlin, see Lindane Formal, see Malathion, Methylal Formaldehyde bis(p-chloroethylacetal), see Bis(2-chloroethoxy) methane Formaldehyde dimethylacetal, see Methylal Formalin, see Formaldehyde Formalin 40, see Formaldehyde Formalith, see Formaldehyde Formic acid, ethyl ester, see Ethyl formate Formic acid, methyl ester, see Methyl formate Formic aldehyde, see Formaldehyde Formic ether, see Ethyl formate Formira, see Formic acid Formisoton, see Formic acid Formol, see Formaldehyde Formosa camphor, see Camphor Formula 40, see 2,4-D... 

Formaldehyde/urea condensate Formaldehyde/urea copolymer Formaldehyde/urea polymer Formaldehyde/urea precondensate Formaldehyde/urea prepolymer Formaldehyde/urea resin. See Urea-formaldehyde resin Formal glycol. See 1,3-Dioxolane Formalin. See Formaldehyde Formalin/urea copolymer. See Urea-formaldehyde resin Formamide... 

Formaldehyde sodium bisulfite adduct Formaldehyde sodium sulfoxylate. See Sodium formaldehyde sulfoxylate Formal glycol. See 1,3-Dioxolane Formalin. See Formaldehyde Formamide, 1,1 -azobis-. See Azodicarbonamide Formic acid, aluminum salt. See Aluminum formate Formic aldehyde Formol. See Formaldehyde p-FormyInitrobenzene. See p-Nitrobenzaldehyde Fossil flour. See Diatomaceous earth Silica, fumed Fossil wax. See Ozokerite Franklin. See Calcium carbonate Free crystalline silica. See Quartz Freon 113. See Trichlorotrifluoroethane P-D-Fructofuranosyl-a-D-glucopyranoside. See Sucrose P-D-Fructofuranosyl-a-D-glucopyranoside benzoate. See Sucrose benzoate P-D-Fructofuranosyl-a-D-glucopyranoside monohexadecanoate. See Sucrose palmitate... 

Spanish) or FORMALINE (German) or FORMALIN LOESUNGEN (German) or FORMALITH (50-00-0) see formaldehyde. FORMAMIDA (Spanish) or FORMAMIDE (75-12-7) CH3NO... 

PBS/formalin Mix 400 mL of autoclaved, deionized water with 50 mL of lOX PBS and 50 mL of formalin (40% formaldehyde solution BDH, cat. no. 10113). Measure 50 mL aliquots using sterile, single-use plasticware. This solution is stable at room temperature but should be checked for contamination prior to use Saline (see Note 4)- 0 9% (w/v) NaCl in RNase-free water Acetylation buffer (see Note 5) O.lMtnethanolamme, 0.25% (v/v) acetic anhydride in saline. To make 500 mL, add 7 mL of triethanolamine solution to 500 mL of 0.9% saline. Immediately before use, add 1.25 mL of acetic anhydride by shaking vigorously for a few seconds. 

Formalin lf6r-mo-lon, - len n [Formalin, a trademark] (1893) (formol) HCHO. Formaldehyde gas commercially available as a 37% wt solution in water with a small amount of methanol for inhibiting polymerization. See Formaldehyde. 

Tubular reactors are used for some polycondensations. Para-blocked phenols can be reacted with formalin to form linear oligomers. When the same reactor is used with ordinary phenol, plugging will occur if the tube diameter is above a critical size, even though the reaction stoichiometry is outside the region that causes gelation in a batch reactor. Polymer chains at the wall continue to receive formaldehyde by diffusion from the center of the tube and can crosslink. Local stoichiometry is not preserved when the reactants have different diffusion coefficients. See Section 2.8. 

Figure 15.8 (a) Time course of the activity restoration of formalin-treated RNase A during incubation at 50°C (0-2h) and 65°C (2-4h) in TAE buffer, pH 7.0. (b) Time course of the activity restoration of formalin-treated RNase A during incubation at 65°C in TAE buffers of various pH values. All RNase A preparations were freed of excess formaldehyde by dialysis prior to the assay. The RNase A activity was determined with a colorimetric assay using cytidine 2,3,-cyclophosphate as the substrate as described by Crook et al.54 Note that the slopes of the curves decrease with incubation time at 65°C, which is near the denaturation temperature of native RNase A. This loss of activity is likely due to the competing effect of protein denaturation of the recovered RNaseA at this temperature. See Rait et al.10 for details. 

Figure 15.13 SDS-PAGE of formalin-fixed RNase A before and after protein retrieval. Lane M molecular weight marker lane 1 native RNase A lane 2 formalin-treated RNase A after the removal of excess formaldehyde by rapid dialysis lane 3 formalin-treated RNase A sample from lane 2 after retrieval in 20 mM Tris-HCl, pH 4.0, with 2% SDS lanes 4,6, and 8 formahn-treated RNase A after incubation in 100% ethanol for lh, 24h, or 1 week, respectively lanes 5, 7, and 9 1-h, 24-h, or 1-week formalin-fixed, ethanol-treated RNase A after retrieval in 20 mM Tris-HCl, pH 4.0, with 2% SDS. All RNase A samples were heated at 100°C for 20min, followed by 60°C for 2h. See Fowler et al.12 for details.

Formalin should always be fresh (see above reference to formaldehyde and formic acid formation with time), and buffered to a pH of 7.0-7.6. As this is a slow reacting fixative, acidic mixtures may induce structural or antigenic changes resulting in poor morphology and low detection. 

Formaldehyde is not available as a pure monomer because it forms trimers and tetramers in the pure state (Chapter 52). The aqueous solution formalin used to preserve biological specimens is available—it is 37% formaldehyde and mostly consists of the hydrate CH2(OH)2 see Chapters. A pure dry polymer paraformaldehyde is also available and was mentioned in Chapter 9, Neither of these is particularly useful in aldol reactions. The aqueous solution is used in the Mannich reaction that we describe shortly. It is possible to make the short-lived monomer and capture it with a lithium enojate, but this is not trivial experimentally. 

Death. Cases of death in humans acutely exposed to airborne formaldehyde were not located. Death after the ingestion of fonnaldehyde (or a formalin solution) in humans has been reported in connection with attempted suicides. Metabolic acidosis has been noted prior to death, along with respiratory, cardiac, and renal failure autopsy revealed corrosive damage to gastrointestinal mucosa (Burkhart et al. 1990 Eells et al. 1981 Koppel et al. 1990). Increased rates of cancer-related mortality associated with occupational exposure to formaldehyde (predominately by inhalation) have been found in some epidemiological studies, but not in others (see Section 2.2.1.8 and Section 2.5). Animal studies indicate that subchronic inhalation exposure to concentrations below 20 ppm are not lethal (Feron et al. 1988 Maronpot et al. 1986 Martin 1990 Rusch et al. 1983 Saillenfait et al. 1989 Woutersen et al. 1987), but lifetime inhalation exposure to formaldehyde has been associated with early mortalities associated with... 

Commercially available formalin is 37—10% formaldehyde ( see Note 1) and may destroy many epitopes. 

Methanol (formaldehyde) is a gas (b.p. —21°C). It is available commercially as an aqueous solution called formalin. Formalin has been used as a preservative for tissues and as an embalming fluid. For other uses of formaldehyde, see A Clinical Perspective Medical Applications of Aldehydes. 

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