Clonogenic assay is otherwise also referred to as a “colony formation,”  this pertains to an in vitro process or survival analysis in order to determine a single cell’s capability to form a specific colony .
A colony refers to fifty cells or more. This process is particularly useful in analyzing the effects of ionization and cytotoxic agents upon the mortality of cell reproduction in culture mediums. Apparently, only a fraction of seeded cells is capable of forming colonies.
Published Clinical Citations
 ^ Fedr, Radek, Zuzana Pernicová, Eva Slabáková, Nicol Straková, Jan Bouchal, Michal Grepl, Alois Kozubík, and Karel Souček. 2013. Automatic cell cloning assay for determining the clonogenic capacity of cancer and cancer stem-like cells. Cytometry. Part A : the journal of the International Society for Analytical Cytology, no. 5 (February 28). doi:10.1002/cyto.a.22273. https://www.ncbi.nlm.nih.gov/pubmed/23450810
 ^ Hauser, Ross A, and Amos Orlofsky. 2013. Regenerative injection therapy with whole bone marrow aspirate for degenerative joint disease: a case series. Clinical medicine insights. Arthritis and musculoskeletal disorders (September 4). doi:10.4137/CMAMD.S10951. https://www.ncbi.nlm.nih.gov/pubmed/24046512
 ^ Nahas, Shareef A, Robert Davies, Francesca Fike, Kotoka Nakamura, Liutao Du, Refik Kayali, Nathan T Martin, Patrick Concannon, and Richard A Gatti. 2011. Comprehensive profiling of radiosensitive human cell lines with DNA damage response assays identifies the neutral comet assay as a potential surrogate for clonogenic survival. Radiation research, no. 2 (September 30). https://www.ncbi.nlm.nih.gov/pubmed/21962002