realizes is about is_specified_output_of concretizes direct assay evidence cell-free assay evidence eco in vitro assay ECO:0000183 A type of direct assay evidence resulting from studies in which cytoplasmic and/or nuclear cellular components from resting, nonstimulated cells, are isolated by ultracentrifugation to provide molecular machinery that can be used in reactions in the absence of many of the other cellular components for the purpose of in vitro protein synthesis, transcription, DNA replication, etc. metabolic process assay in container assay in vitro design