Tricine: A Versatile Buffer in Biochemical Research

What is Tricine and how does it function as a buffer?

Tricine, chemically known as N-[Tris(hydroxymethyl)methyl]glycine, is a zwitterionic buffer with a pKa of approximately 8.05 at 25°C. Its zwitterionic nature allows it to maintain pH stability in the physiological and slightly alkaline range (7.0–9.0), making it ideal for applications such as SDS-PAGE, where pH control is critical for consistent protein separation. Tricine is particularly effective in low ionic strength environments, reducing ionic interference and improving resolution in electrophoretic systems. It is often used in place of Tris or HEPES when higher buffering capacity at alkaline pH is required.

Why is Tricine preferred in protein electrophoresis?

In SDS-PAGE, Tricine is commonly used in the running buffer for the resolving gel, especially in the separation of low-molecular-weight proteins (below 10 kDa). Its buffering capacity and low ionic strength enhance resolution and reduce band broadening. Tricine-based systems, such as the Laemmli system with Tricine in the running buffer, are standard in protocols for high-resolution separation of small proteins and peptides. Additionally, Tricine is less likely to interfere with downstream analyses such as mass spectrometry due to its low molecular weight and minimal background signal.

Related concepts

Tricine is frequently used alongside other buffers like HEPES and Tris, and is compatible with common reagents such as SDS, glycerol, and reducing agents (e.g., DTT, TCEP). It is available in high-purity grades suitable for research and regulatory compliance (e.g., ACS, USP, EP). Its stability and solubility in aqueous solutions make it a reliable choice in both laboratory and industrial settings.