4% Paraformaldehyde PFA

Paraformaldehyde (PFA) is a linear polymer, cross-linking fixative that changes to formaldehyde upon heating and by adding small amount of sodium hydroxide. Paraformaldehyde is the polymerization product of formaldehyde; degree of polymerization of 8–100 units. It must be depolymerized to formaldehyde in solution prior to use since it is not the fixative itself. The formaldehyde fixing procedure for cell samples usually involves using a 4% formaldehyde solution in phosphate buffered saline (PBS) on ice for a few minutes. This vital step maintains the cell morphology and therefore ensures that sample cell structures stay intact, and antigens are immobilized, while still permitting antibody-target antigen access.

We supply 4% Paraformaldehyde as a methanol-free, ready-to-use fixative that functions by forming covalent cross-links between molecules. This strong network stabilizes the cellular framework, thus effectively preserving cell and tissue components. The fixative delivers consistency in maintaining the physical and chemical properties of the cell; no evident changes occur in the chemical and morphological characteristics of the cell/tissue specimens on exposure to the product. It is compatible with several antibody-based detection methods, such as immunohistochemistry, immunocytochemistry, and immunofluorescence.

4% Paraformaldehyde solution is widely used in the detection of tissue, tissue slice, cell, and other biological sample fixation solutions such as immunohistochemistry. 4% Paraformaldehyde solution fixes the cells or tissue samples need to be repaired before immunostaining or other subsequent procedures. Our 4% paraformaldehyde (PFA) w/v is a ready-to-use solution, prepared in 0.1M Phosphate buffer (PB) and free of methanol and DEPC. The 4% solution of Paraformaldehyde is prepared from granular paraformaldehyde that is dissolved in 0.1 M Phosphate buffer (PB), pH 7.4. The 4% Paraformaldehyde solution has strong penetrability and fixation, which can make the tissue harden and it is good for slicing. In addition, 4% Paraformaldehyde can be used to fix and preserve fat and lipid substances.

Applications:
• for use in the preparation of formalin fixatives for tissues or cells when the samples are to be used in florescence imaging
• for fixing of cell/tissue sections during histology/staining procedures
• for cross-linking cells during chromatin immunoprecipitation (ChIP) assay

PRODUCT CITATIONS:

1. Park, Sang-Won (2023) Development of new tools to study membrane-anchored mammalian Atg8 proteins. AUTOPHAGY. https://doi.org/10.1080/15548627.2022.2132040