[Ca2+]	Calcium ion concentration
[K+]	Potassium ion concentration
[K+]i	Intracellular potassium ion concentration
[Mg2+]	Magnesium ion concentration
[Mg2+]i	Intracellular magnesium ion concentration
[Na+]	Sodium ion concentration
[Na+]ex	Extracellular sodium ion concentration
[Zn2+]	Zinc ion concentration
[Zn2+]i	Intracellular zinc ion concentration
ACE	Angiotensin-converting enzyme
Ag+	Silver ion
APG-1	Asante potassium green-1
BON	Bacterial OsmY and nodulation
Ca2+	Calcium ion
CaM	Calmodulin
Cd2+	Cadmium ion
CFP	Cyan fluorescent protein
Co2+	Cobalt ion
Cu+/Cu2+	Copper ions
ECF	Extracellular fluid
EMRE	Essential mitochondrial calcium uniporter regulator
ER	Endoplasmic reticulum
Fe2+/Fe3+	Iron ions
FP	Fluorescent protein
FRET	Förster resonance energy transfer
GEP	Genetically encoded probe
GEPII	Genetically encoded potassium ion indicator
GFP	Green fluorescent protein
K+	Potassium ion
Kbp	Potassium ion binding protein
KD	Dissociation rate constant
lc-	Low charge
LysM	Lysine motife
MARIO	Magnesium ratiometric indicator for optical imaging
MCU	Mitochondrial calcium uniporter
Mg2+	Magnesium ion
MICU1/2	Mitochondrial calcium uptake 1 and 2
Mn2+	Manganese ion
Na+	Sodium ion
Pb2+	Plumb ion
RFP	Red fluorescent protein
ROS	Reactive oxygen species
RpoS	RNA polymerase sigma S
TCR	T-cell receptor
TnC	Troponin C
YFP	Yellow fluorescent protein
Zn2+	Zinc ion