Figure 1.

An overview of CR technology, involving collection and preparation of clinical specimens, processing of feeder cells, and establishment of co-cultures. Tissues of interest are obtained from human surgical resected specimen, core biopsy, needle puncture, brushings, effusion, patient-derived xenograft (PDX) tissue, or from animal origins. Some samples require a thorough assessment by pathologists to distinguish between normal and pathological tissues. Tissues are diced and digested enzymatically for 1–3 h to collect the primary suspension cells. Co-culture of the primary cells includes the irradiated or mitomycin C-treated mouse 3T3-J2 fibroblasts and Y-27632 in the CR system. Of note, J2 feeder-conditioned medium can also be used for CR culture.