Most commonly used buffers in protein extraction are HEPES or TRIS buffers.
HEPES buffer is so-called “Good” buffer for biochemical and biological research, as defined by Norman Good and colleagues (Good et al., 1966; Good and Izawa, 1972). Among other criteria, Good buffers have excellent buffering properties that are independent of temperature and concentration, are readily soluble in water, and are biologically and chemically inert.
Disadvantages of TRIS buffer:
In the light of these clear disadvantages, TRIS is not considered a Good buffer for biochemical and biological research (Good et al., 1966; Stoll and Blanchard, 2009).
HEPES buffer is so-called “Good” buffer for biochemical and biological research, as defined by Norman Good and colleagues (Good et al., 1966; Good and Izawa, 1972). Among other criteria, Good buffers have excellent buffering properties that are independent of temperature and concentration, are readily soluble in water, and are biologically and chemically inert.
Disadvantages of TRIS buffer:
- Reduced buffering capacity below pH 7.5
- pKa is temperature dependent which means, that if a TRIS buffer solution is made up and adjusted to pH 8.06 at 25°C, its pH will increase significantly to pH 8.85 at 0°C (Stoll and Blanchard, 2009).
- The pH of Tris decreases around 0.1 pH unit for each 10-fold dilution.
In the light of these clear disadvantages, TRIS is not considered a Good buffer for biochemical and biological research (Good et al., 1966; Stoll and Blanchard, 2009).