{"product_id":"formaldehyde-10-methanol-free-ph-5-6","title":"Formaldehyde 10%, Methanol-Free, pH 5–6","description":"\u003cp\u003eFormaldehyde, 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.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eNote, 04018 Formaldehyde, 10%, methanol-free, Ultra Pure, pH 6.2-7.4 is available \u003ca href=\"https:\/\/polysciences.com\/products\/formaldehyde-10-methanol-free-ultra-pure\" target=\"_blank\" title=\"Buy 10% Methanol-Free Formaldehyde, Ultra Pure | Polysciences\" rel=\"noopener\"\u003ehere\u003c\/a\u003e.\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eThe 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.\u003c\/p\u003e\n\u003cp\u003eFormaldehyde 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.\u003c\/p\u003e\n\u003ch2\u003eKey Properties\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eProduct number: 04019\u003c\/li\u003e\n\u003cli\u003eCAS number: 50-00-0\u003c\/li\u003e\n\u003cli\u003eFormaldehyde formula: CH\u003csub\u003e2\u003c\/sub\u003eO\u003c\/li\u003e\n\u003cli\u003eFormaldehyde concentration: 10% (w\/v equivalent)\u003c\/li\u003e\n\u003cli\u003eSupplied pH: 5–6\u003c\/li\u003e\n\u003cli\u003eMethanol content: Methanol-free\u003c\/li\u003e\n\u003cli\u003eGrade: Ultra Pure\u003c\/li\u003e\n\u003cli\u003eAppearance: Clear, colorless liquid\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eApplications\u003c\/h2\u003e\n\u003ch3\u003eLight Microscopy Fixation\u003c\/h3\u003e\n\u003cp\u003eUse 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.\u003c\/p\u003e\n\u003ch3\u003eElectron Microscopy \u0026amp; Perfusion Fixation\u003c\/h3\u003e\n\u003cp\u003eUse 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.\u003c\/p\u003e\n\u003ch3\u003eKarnovsky-Type Fixative Preparation\u003c\/h3\u003e\n\u003cp\u003eCombine with glutaraldehyde and a suitable buffer to prepare a Karnovsky-type fixative according to an established formulation. For a packaged alternative, explore the \u003ca href=\"\/products\/karnovskys-fixative\"\u003eKarnovsky’s Fixative Kit\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eFormulation \u0026amp; Fixation Considerations\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eThe supplied solution contains 10% formaldehyde; it is not equivalent to 10% formalin, which typically contains approximately 4% formaldehyde\u003c\/li\u003e\n\u003cli\u003eAccount for dilution by buffer, glutaraldehyde, and other components when calculating the final formaldehyde concentration\u003c\/li\u003e\n\u003cli\u003eConfirm the final working pH after preparing the complete fixative\u003c\/li\u003e\n\u003cli\u003eFollow the protocol’s requirements for specimen dimensions, fixation time, temperature, and perfusion or immersion conditions\u003c\/li\u003e\n\u003cli\u003eUse the aqueous solution directly as a formulation ingredient; no paraformaldehyde depolymerization step is required\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eStorage \u0026amp; Product Selection\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eStore tightly sealed at room temperature\u003c\/li\u003e\n\u003cli\u003eLimit prolonged exposure to air, which can promote oxidation of formaldehyde to formic acid\u003c\/li\u003e\n\u003cli\u003eAvoid cold storage, which can promote formation of a white precipitate\u003c\/li\u003e\n\u003cli\u003eFormaldehyde is carcinogenic and can cause irritation and skin sensitization; use a chemical fume hood, compatible protective gloves, chemical splash goggles, and protective clothing\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/pages\/contact-us\" title=\"Contact Us form\" rel=\"noopener\" target=\"_blank\"\u003eContact Polysciences to request the current SDS and product documentation for catalog 04019\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003eFor quantity requirements, \u003ca href=\"\/pages\/contact-us?inquiry_type=Bulk+Inquiry\"\u003erequest a bulk quote\u003c\/a\u003e and specify Formaldehyde, 10%, methanol-free, Ultra Pure, pH 5–6, catalog 04019\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr class=\"pdp-divider\"\u003e\n\u003ch3\u003eWhy Choose Polysciences?\u003c\/h3\u003e\n\u003cdiv class=\"pdp-trust-signals\" style=\"display: grid; grid-template-columns: repeat(2,1fr); gap: 14px; max-width: 560px; margin: 24px 0;\"\u003e\n\u003cdiv style=\"border: 1px solid #17458f; border-radius: 10px; padding: 18px 14px; text-align: center; background: #fff;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0713\/5258\/2358\/files\/Research_Labs.png?v=1778099422\" alt=\"Research laboratories icon\" style=\"width: 42px; height: 42px; object-fit: contain; display: block; margin: 0 auto 12px;\"\u003e\n\u003cdiv style=\"font-family: inherit; font-size: 14px; line-height: 1.3; font-weight: bold; color: #12386b;\"\u003eTrusted by 6,000+ Researchers Worldwide\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #17458f; border-radius: 10px; padding: 18px 14px; text-align: center; background: #fff;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0713\/5258\/2358\/files\/Peer-Reviewed.png?v=1778099423\" alt=\"Peer reviewed studies icon\" style=\"width: 42px; height: 42px; object-fit: contain; display: block; margin: 0 auto 12px;\"\u003e\n\u003cdiv style=\"font-family: inherit; font-size: 14px; line-height: 1.3; font-weight: bold; color: #12386b;\"\u003eCited in Thousands of Peer-Reviewed Studies\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #17458f; border-radius: 10px; padding: 18px 14px; text-align: center; background: #fff;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0713\/5258\/2358\/files\/USA.png?v=1778099422\" alt=\"Made in USA icon\" style=\"width: 42px; height: 42px; object-fit: contain; display: block; margin: 0 auto 12px;\"\u003e\n\u003cdiv style=\"font-family: inherit; font-size: 14px; line-height: 1.3; font-weight: bold; color: #12386b;\"\u003eU.S. Manufacturing \u0026amp; Global Distribution\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #17458f; border-radius: 10px; padding: 18px 14px; text-align: center; background: #fff;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0713\/5258\/2358\/files\/Delivery.png?v=1778099422\" alt=\"Global delivery icon\" style=\"width: 42px; height: 42px; object-fit: contain; display: block; margin: 0 auto 12px;\"\u003e\n\u003cdiv style=\"font-family: inherit; font-size: 14px; line-height: 1.3; font-weight: bold; color: #12386b;\"\u003eReliable Delivery to 40+ Countries\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch2\u003eFAQ\u003c\/h2\u003e\n\u003cp\u003eClick a question to expand.\u003c\/p\u003e\n\u003cdiv class=\"faq-accordion\"\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003e1. What is this formaldehyde solution used for?\u003c\/summary\u003e\n\u003cp\u003eThis 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.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003e2. Is 10% formaldehyde the same as 10% formalin?\u003c\/summary\u003e\n\u003cp\u003eNo. This solution contains 10% formaldehyde. Conventional 10% formalin typically contains approximately 4% formaldehyde. Calculate dilutions using the formaldehyde concentration required by the protocol.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003e3. What does the pH 5–6 designation mean?\u003c\/summary\u003e\n\u003cp\u003eThe 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.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003e4. Does this solution require paraformaldehyde depolymerization?\u003c\/summary\u003e\n\u003cp\u003eNo. The formaldehyde is already in aqueous solution. It can be used as a formulation ingredient without first dissolving and depolymerizing paraformaldehyde.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003e5. Can it be used to prepare a Karnovsky-type fixative?\u003c\/summary\u003e\n\u003cp\u003eYes. 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.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003e6. How should this formaldehyde solution be stored?\u003c\/summary\u003e\n\u003cp\u003eStore 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.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails open=\"\"\u003e\n\u003csummary\u003e7. Where can I obtain the SDS?\u003c\/summary\u003e\n\u003cp\u003e\u003ca href=\"\/pages\/contact-us\"\u003eContact Polysciences\u003c\/a\u003e to request the current Safety Data Sheet for Formaldehyde, 10%, methanol-free, Ultra Pure, pH 5–6, catalog 04019.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e","brand":"Polysciences","offers":[{"title":"04019-3.75","offer_id":67617261977814,"sku":"04018-1","price":584.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0713\/5258\/2358\/files\/04018_1_1_562ba929-c53f-4246-8a76-42e0af750eaf.gif?v=1735828722","url":"https:\/\/polysciences.com\/products\/formaldehyde-10-methanol-free-ph-5-6","provider":"Polysciences","version":"1.0","type":"link"}