Table 2.

Design of LC-MS/MS-based deiodinase assays

	HepG2	Mouse liver	MSTO-211H	ECC-1	HEK293
pH of homogenization buffer	7.4	7.4	7.4	8.0	7.4 or 8.0a
Amount of protein per reaction (μg)	300	40	2000	600	40–2000a
pH of potassium phosphate buffer	6.8	6.8	6.8	8.0	6.8 or 8.0a
[DTT] in potassium phosphate buffer (mm)	33	33	33	83	33 or 83a
Final [substrate] (μm)	0.05–20	0.05–20	0.01–0.5	0.01–5	0.01–20a
Incubation time (min)	30–120	15–120	30–120	30–120	15–120a

^aAdapted to the conditions used in the respective series of samples.