Formaldehyde 10%, Methanol-Free, pH 5–6

Formaldehyde, 10%, methanol-free, Ultra Pure, pH 5–6, is an aqueous formaldehyde solution derived from paraformaldehyde for light and electron microscopy fixation workflows. The clear, colorless solution provides a liquid source of formaldehyde without requiring dissolution and depolymerization of paraformaldehyde before formulation. Note, 04018 Formaldehyde, 10%, methanol-free, Ultra Pure, pH 6.2-7.4 is available here. The solution can be diluted and combined with a user-selected buffer to prepare a working fixative. Its supplied pH of 5–6 should be distinguished from the final pH required by the fixation protocol. Formaldehyde can also be combined with glutaraldehyde in dual-aldehyde fixation systems, including Karnovsky-type formulations and protocols for delicate tissues such as brain. Final aldehyde concentrations, buffer composition, and fixation conditions should follow the intended microscopy method. Key Properties Product number: 04019 CAS number: 50-00-0 Formaldehyde formula: CH2O Formaldehyde concentration: 10% (w/v equivalent) Supplied pH: 5–6 Methanol content: Methanol-free Grade: Ultra Pure Appearance: Clear, colorless liquid Applications Light Microscopy Fixation Use as a formaldehyde source for preparing tissue fixatives for histological specimens. Adjust the working concentration and buffer according to the tissue, specimen dimensions, and downstream staining or imaging method. Electron Microscopy & Perfusion Fixation Use in formaldehyde–glutaraldehyde fixation protocols for ultrastructural studies, including vascular perfusion methods for delicate tissues such as brain. Specimen preparation and fixation conditions should be selected for the tissue and the required structural preservation. Karnovsky-Type Fixative Preparation Combine with glutaraldehyde and a suitable buffer to prepare a Karnovsky-type fixative according to an established formulation. For a packaged alternative, explore the Karnovsky’s Fixative Kit. Formulation & Fixation Considerations The supplied solution contains 10% formaldehyde; it is not equivalent to 10% formalin, which typically contains approximately 4% formaldehyde Account for dilution by buffer, glutaraldehyde, and other components when calculating the final formaldehyde concentration Confirm the final working pH after preparing the complete fixative Follow the protocol’s requirements for specimen dimensions, fixation time, temperature, and perfusion or immersion conditions Use the aqueous solution directly as a formulation ingredient; no paraformaldehyde depolymerization step is required Storage & Product Selection Store tightly sealed at room temperature Limit prolonged exposure to air, which can promote oxidation of formaldehyde to formic acid Avoid cold storage, which can promote formation of a white precipitate Formaldehyde is carcinogenic and can cause irritation and skin sensitization; use a chemical fume hood, compatible protective gloves, chemical splash goggles, and protective clothing Contact Polysciences to request the current SDS and product documentation for catalog 04019 For quantity requirements, request a bulk quote and specify Formaldehyde, 10%, methanol-free, Ultra Pure, pH 5–6, catalog 04019 Why Choose Polysciences? Trusted by 6,000+ Researchers Worldwide Cited in Thousands of Peer-Reviewed Studies U.S. Manufacturing & Global Distribution Reliable Delivery to 40+ Countries FAQ Click a question to expand. 1. What is this formaldehyde solution used for? This methanol-free aqueous formaldehyde solution is used to prepare fixatives for light and electron microscopy. It can also be combined with glutaraldehyde and a user-selected buffer for dual-aldehyde fixation protocols. 2. Is 10% formaldehyde the same as 10% formalin? No. This solution contains 10% formaldehyde. Conventional 10% formalin typically contains approximately 4% formaldehyde. Calculate dilutions using the formaldehyde concentration required by the protocol. 3. What does the pH 5–6 designation mean? The pH 5–6 designation applies to the supplied solution. Dilution and addition of buffer or other fixative components can change the pH, so confirm the final working pH before use. 4. Does this solution require paraformaldehyde depolymerization? No. The formaldehyde is already in aqueous solution. It can be used as a formulation ingredient without first dissolving and depolymerizing paraformaldehyde. 5. Can it be used to prepare a Karnovsky-type fixative? Yes. Combine the formaldehyde solution with glutaraldehyde and an appropriate buffer according to the selected formulation. Account for the concentration and volume of each component when preparing the working fixative. 6. How should this formaldehyde solution be stored? Store tightly sealed at room temperature. Limit prolonged exposure to air and avoid cold storage, which can promote precipitation. Contact Polysciences for guidance if the solution develops visible precipitate or changes in appearance. 7. Where can I obtain the SDS? Contact Polysciences to request the current Safety Data Sheet for Formaldehyde, 10%, methanol-free, Ultra Pure, pH 5–6, catalog 04019.