Table 1.

Stage I LoC characterization guidelines by IQ-MPS [34].

Functional marker	Specifications
Albumin secretion	37–105 μg/day/million cells (should be stable across 14 days of culture duration, less than 50 % change over a 14 days period with less than 30 % C.V. of mean daily production rates)
Urea secretion	56–159 μg/day/million cells (should be stable across 14 days of culture duration, less than 50 % change over a 14 days period with less than 30 % C.V. of mean daily production rates)
Gene expression of enzymes and transporters should be stable over time (levels should be comparable to cryopreserved hepatocyte in freshly prepared suspension) Baseline enzyme activity can also be measured and compared with fresh hepatocytes (part of stage II guidelines)	Phase I enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4), phase II enzymes (UGT1A1, GSTA1), uptake transporters (SLCO1B1, SLCO1B3, SLC22A1), and efflux transporters (ABCC2, ABCG2, ABCB1, ABCB11)