Thermo Scientific™ Pierce™ 16% Formaldehyde (w/v), Methanol-free

Catalog No.	Quantity
PI28906	10 x 1 mL
PI28908	10 x 10 mL

Catalog No. PI28906 Supplier Thermo Scientific™ Supplier No. 28906

Description

Vials of high-quality, methanol-free formaldehyde, a general IHC fixative and reversible amine-crosslinking agent for protein and nucleic acid samples.

Thermo Scientific™ Pierce Formaldehyde Ampules are vials of high-quality, methanol-free formaldehyde for use as a general immunohistochemistry fixative and reversible amine-crosslinking agent for protein and nucleic acid tissue samples.

Formaldehyde is a highly reactive, cell-permeable agent that is used as a reversible cross-linking agent for proteins and nucleic acids within the cell or as a general cell-fixing agent for imaging-based applications. Cell permeability allows the reagent to readily enter living cells, enabling intracellular applications, such as protein interaction discovery or bioimaging. Formaldehyde produces reversible cross-links with protein and nucleic acids by coupling neighboring primary amines. Cross-links can be reversed simply by heating the sample.

Highlights:

• Pure and stable - prepared directly from pure granular paraformaldehyde and sealed in ampules under an inert atmosphere, ensuring that it is methanol-free and resistant to oxidation

• Versatile - use to cross-link molecules in protein-protein and protein-nucleic acid interaction discovery, bioimaging and flow cytometry

• Aliquot packaging - choose 1mL or 10mL ampules suitable for low- and high-volume applications ranging from culture-targeted cell fixing to in-cell protein cross-linking

• Convenient starting concentration - 16% (w/v) formaldehyde solution in ultrapure water simplifies dilution to the required working concentration

Specifications

• Chemical Name or Material: Formaldehyde
• Quantity: 10 x 1 mL
• Physical Form: Liquid
• Product Line: Pierce

Frequently Asked Questions (FAQs)

Where do I find the expiry date of Pierce 16% Formaldehyde (w/v), Methanol-free (Cat. No. 28906)?

We guarantee the functionality of Pierce 16% Formaldehyde (w/v), Methanol-free for one year from date of shipment, if stored correctly. See Limited Warranties for consumables under the General Terms and Conditions of Sale.

What are the options for crosslinking proteins to nucleic acids, and what are the differences between them?

We offer the following crosslinkers for protein to nucleic acids: formaldehyde (Cat. No. 28906), SPB (Cat. No. 23013), SDAD (Cat. No. 26169), sulfo-SDAD (Cat. No. 26175), and sulfo-SBED (Cat. No. A39260).
Formaldehyde can be used for DNA-DNA crosslinking as well as DNA-protein crosslinking. While it is good for crosslinking proteins that are in direct contact with DNA, formaldehyde cannot link proteins that may be bound in a complex with other proteins but are not in direct contact with DNA. EGS or DSG can crosslink proteins to other proteins that are in direct contact with DNA and crosslinked to DNA by formaldehyde.
SPB, Sulfo-SDAD, and Sulfo-SBED are all photoreactive crosslinkers. SPB is an NHS-ester and psoralen heterobifunctional crosslinker that conjugates primary amines on proteins to DNA via photo-activated intercalation of psoralen to pyrimidine bases. The psoralen tricyclic planar ring system intercalates into double-stranded, and to a lesser extent, single-stranded DNA and RNA. The photoreactive psoralen group provides more selective covalent binding to nucleic acids than either phenyl azide or diazerine linkers, which makes SPB the best choice. The diazerine on sulfo-SDAD and the phenyl azide on sulfo-SBED are not selective for nucleic acids and can crosslink other biomolecules in the same besides any protein-DNA interactions. Sulfo-SBED involves biotin transfer rather than actual linking.

What fixative should I use to fix my cells or tissues for antibody labeling?

Aldehyde-based fixatives (e.g., formaldehyde, glutaraldehyde) crosslink various cellular components, which helps retain proteins and cell morphology, but some antigens can be masked by the crosslinking, requiring antigen retrieval methods to unmask the antigen binding sites. Also, aldehyde-based fixation requires permeabilization to allow entry of antibodies. Organic solvents such as methanol and acetone condense proteins and permeabilize the cells, but cell morphology can be compromised. Surface antigens can be labeled without fixation.

What is the difference between formalin and formaldehyde?

The terms “formalin” and “formaldehyde” are often used interchangeably, although the chemical composition of each fixative is different. Formalin is made with formaldehyde but the percentage denotes a different formaldehyde concentration than formaldehyde solutions. For example, 10% neutral-buffered formalin (NBF or simply formalin) is really a 4% formaldehyde solution; the basis for this difference is that historically, formalin was prepared with commercial-grade stock formaldehyde, which is 37 to 40% formaldehyde, by diluting it 1:10 in phosphate buffer.

What is the difference between Formaldehyde and Paraformaldehyde?

Most commercial formaldehyde is prepared with paraformaldehyde (polymeric formaldehyde) dissolved in distilled/deionized water, with methanol added to stabilize the aqueous formaldehyde. Solution stabilization is important to prevent oxidation to formic acid and the eventual repolymerization to paraformaldehyde, and therefore commercial formaldehyde may contain up to 10% methanol. To avoid using methanol-contaminated formaldehyde for fixation, many protocols recommend making “fresh” formaldehyde from paraformaldehyde immediately before sample fixation. This preparation is not necessary if using Cat. Nos. 28906 and 28908.

What are storage conditions for 16% Formaldehyde?

We recommend storing in the original container protected from direct sunlight in a dry, cool and well-ventilated area.

What is a feature of the Thermo Scientific 16% Formaldehyde (w/v), Methanol-free formulation?

Thermo Scientific 16% Formaldehyde (w/v), Methanol-free is carefully prepared directly from granular paraformaldehyde and sealed under an inert atmosphere in 1 mL and 10 mL ampules. Solution stabilization is important because formaldehyde solutions oxidize to formic acid and eventually repolymerize to paraformaldehyde. Ampule packaging under an inert atmosphere stabilizes the preparation by protecting the solution from both air oxidation and light, allowing access to “fresh” formaldehyde every time. This saves valuable time and eliminates the need and hazards associated with preparing the solution directly from paraformaldehyde. The convenient starting concentration of 16% w/v formaldehyde solution simplifies dilution to the required working concentration.

What is the primary use for 16% Formaldehyde?

Formaldehyde is used as a general IHC fixative and reversible amine-crosslinking agent for cells, protein and nucleic acid tissue samples. As a cell-permeable and reversible protein and nucleic acid crosslinking agent , it couples primary amines that are within proximity of each formaldehyde molecule. Cell permeability allows the reagent to readily enter living cells, enabling intracellular applications such as protein interaction discovery or bioimaging. Formaldehyde crosslinks can be reversed simply by heating the sample.

Safety and Handling

WARNING: Cancer - www.P65Warnings.ca.gov

For Research Use Only. Not for use in diagnostic procedures.