Finesse, Thermo Fisher Scientific 2 articles published in JoVE Bioengineering Power Input Measurements in Stirred Bioreactors at Laboratory Scale Stephan C. Kaiser1, Sören Werner2, Valentin Jossen2, Katharina Blaschczok2, Dieter Eibl2 1Finesse, Thermo Fisher Scientific, 2Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, School of Life Sciences and Facility Management The power input in stirred bioreactors can be measured through the torque that acts on the impeller shaft during rotation. This manuscript describes how an air bearing can be used to effectively reduce friction losses observed in mechanical seals and improve the accuracy of power input measurements in small-scale vessels. Developmental Biology Feeder-free Derivation of Melanocytes from Human Pluripotent Stem Cells Scott J. Callahan1,2, Yvonne Mica3, Lorenz Studer1 1The Center for Stem Cell Biology, Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 2Cancer Biology and Genetics Program, Gerstner Sloan-Kettering Graduate School, Sloan-Kettering Institute for Cancer Research, 3Thermo Fisher Scientific This work describes an in vitro differentiation protocol to produce pigmented, mature melanocytes from human pluripotent stem cells via a neural crest and melanoblast intermediate stage using a feeder-free, 25 day protocol.