. Author manuscript; available in PMC: 2022 Mar 25.

Published in final edited form as: AIMS Biophys. 2015 Aug 14;2(3):336–342. doi: 10.3934/biophy.2015.3.336

Table 1.

Physical Properties of buffers.

Buffer	pKa at 25°C	dpKa/°C at pH 7.0	MW	Metal Binding
Bis-Tris	6.46	N/A	209.24	Negligible¹
HEPES	7.55	−0.014	238.3	Negligible¹
MES	6.15	−0.011	195.2	Negligible¹
NaAc	4.76	Negligible¹	82.03	Negligible¹
Tricine	8.05	−0.021	179.2	Ca²⁺, Mg²⁺, Mn²⁺, Cu²⁺
Tris	8.06	−0.028	121.14	Negligible¹
	Buffer Range
UB1^a	3.0–9.0	−0.015		Ca²⁺, Mg²⁺, Mn²⁺, Cu²⁺
UB2^b	3.5–9.2	−0.020		Negligible¹
UB3^c	2.0–8.2	−0.012		Negligible¹
UB4^c	2.0–8.2	−0.012		Negligible¹

^a.

20mM Tricine, 20mM Bis-Tris, and 20mM sodium acetate,

^b.

20mM Tris-HCl, 20mM Bis-Tris, and 20mM sodium acetate.

^c.

20mM HEPES, 20mM Bis-Tris, and 20mM sodium acetate.

^d.

20mM HEPES, 20mM MES, and 20mM sodium acetate

^1.

Negligible in standard biophysical assays [12, 14.15]