Principle:
Starting with the human tumor xenografts from nude mice (1), tumor cell suspensions are prepared (2) and incubated on 24 well plates containing layers of soft agar. Under these conditions a special subpopulation of cells selectively grows to colonies (3). Normally compounds are tested in 6 concentrations in a panel of 12, 24 or more than 40 different tumors. At your request, we can also arrange a specific selection of suitable tumors based on the expression results from the micro array and/or the gene expression data or the activity data from the monolayer assay.

As this assay is based on human xenografts it combines the advantages of a high correlation of drug response to the same tumor growing in vivo or in the patient, while having moderate time and running expenditures. In contrast to cell line derived xenografts, in the clonogenic assay Oncotest uses human tumor derived xenografts and keeps them at low passages. Thus, if drugs are tested in vitro the correct prediction for positive response and resistance are 65 % and 92 %, respectively.