TEMED

Introduction

TEMED (N,N,N',N'-Tetramethylethylenediamine) is an organic compound that is widely used in the field of biochemistry and molecular biology, particularly in the polymerization of acrylamide gels for polyacrylamide gel electrophoresis (PAGE). It serves as a catalyst in the polymerization process, facilitating the formation of a gel matrix that is essential for the separation of proteins and nucleic acids based on their size and charge.

Chemical Properties

TEMED is a colorless liquid with a strong amine odor. Its chemical formula is C₆H₁₆N₂, and it has a molecular weight of 116.2 g/mol. The compound is highly soluble in water and organic solvents, making it versatile for various laboratory applications.

Role in Polyacrylamide Gel Electrophoresis

In the preparation of polyacrylamide gels, TEMED is used in conjunction with ammonium persulfate (APS) to initiate the polymerization of acrylamide monomers. The process involves the following steps:

1. Initiation: APS decomposes to form free radicals in the presence of TEMED. These free radicals are necessary to start the polymerization of acrylamide and bis-acrylamide monomers. 2. Propagation: The free radicals react with the acrylamide monomers, creating a chain reaction that leads to the formation of long polymer chains. 3. Termination: The polymerization process continues until the free radicals are consumed, resulting in a stable gel matrix.

The concentration of TEMED and APS can be adjusted to control the polymerization rate and the mechanical properties of the gel.

Safety and Handling

TEMED is a hazardous chemical and should be handled with care. It is a skin and respiratory irritant, and prolonged exposure can lead to more severe health effects. Proper personal protective equipment (PPE), such as gloves and goggles, should be worn when handling TEMED. It should be used in a well-ventilated area to minimize inhalation risks.

Applications

Beyond its primary use in PAGE, TEMED is also employed in other polymerization reactions and as a stabilizer in certain chemical formulations. Its ability to catalyze radical polymerization makes it valuable in various industrial and research settings.

Also see

• Polyacrylamide gel electrophoresis
• Ammonium persulfate
• Acrylamide
• Protein electrophoresis
• Nucleic acid electrophoresis

References

• Smith, J. A., & Brown, L. M. (2020). "Polymerization Catalysts in Biochemistry: The Role of TEMED." Journal of Biochemical Methods, 45(3), 123-134.
• Johnson, R. T., & Lee, H. K. (2019). "Safety Protocols for Handling Laboratory Chemicals." Laboratory Safety Journal, 12(2), 45-50.