Table 1.

Compositions of tested buffer solutions

Buffer solution (abbra)	Composition	[Na+] (mM)	[K+] (mM)	[Total monovalent cations] (mM)	[Ca2+] (mM)	[Mg2+] (mM)	Reference
Tricine buffer (TB)	5 mM Tricine, 5 mM KCl		5	5			51
20 mM Ca2+ solution (20 Ca2+)	5 mM Tricine, 5 mM KCl, 20 mM CaCl2		5	5	20		51
40 mM K+ solution (40 K+)	2.5 mM MgCl2, 20 mM KH2PO4, 20 mM KCl, 5 mM Na2HPO4	5	40	45		2.5	51
Bonner solution (BS)	2.7 mM CaCl2, 10 mM KCl, 10 mM NaCl	10	10	20	2.7		11
Developmental buffer (DB)	5 mM Na2HPO4, 5 mM NaH2PO4, 2 mM MgSO4, 200 μM CaCl2	15		15	0.2	2.5	23
Sorenson buffer (SB)	2.7 mM Na2HPO4, 14 mM KH2PO4	5.4	14	19.4			100
KK2 (KK)	3.9 mM K2HPO4, 16.5 mM KH2PO4, 2 mM MgSO4, 0.1 mM CaCl2		24.3	24.3	0.1	2.5	46
Phosphate buffer (PB)	4 mM Na2HPO4, 7.4 mM KH2PO4	8	7.4	15.4			14
DB minus divalent cations (DB-DC)	5 mM Na2HPO4, 5 mM NaH2PO4	15		15			55
Barber buffer (BB)	20 mM KH2PO4, 20 mM K2HPO4		60	60			64

^aabbr, abbreviation.