The power of single colony analysis

Abstract

Human embryonic stem (hES) cells are capable of differentiating into a wide range of specialized cell types. Analysis of hES cells at the single colony or single cell level under cultured conditions is critical to understanding the molecular basis of hES cell differentiation. We have developed a new approach, in which single colonies of cultured hES cells can be picked up, reseeded, and subjected to a variety of analyses, such as immunofluorescent staining and atomic force microscopy. Immunofluorescent staining is a technique which can detect cellular specific proteins with fluorescent tagged antibodies. We found undifferentiated hES cells have a strong cell surface marker, TRA-1-81. However, most of these markers disappeared as the hES cells were cultured in sub-optimal condition for 7 days. Therefore, this method can provide an easy assay to monitor the progress of hES cell differentiation at the single colony or signal cell level.