Methods are disclosed for identifying agents for the treatment of cancer and/or Fanconi anemia using Xenopus egg cell free extracts from which the endogenous DNA has been removed. The assays and method described herein are easily adaptable to high throughput techniques for example to screen large numbers of agents as possible agents for the treatment of cancer and/or Fanconi anemia. Kits for carrying out the disclosed assays and methods also are disclosed. Agents identified by these methods are also disclosed as are methods for treating a subject with cancer and/or Fanconi anemia with these agents.