The current statistical data on mortality and morbidity cases of cancer indicates that there is a worldwide threat of different types of cancers. On this background, there is an urgent need to search for an effective and safe anticancer agent in order to avoid drawbacks of anticancer agents like side effects, ineffectiveness, and cost. Searching for natural sources of anticancer metabolites is one of the most promising ways in current situations. Among these natural sources like plants, animals, and microbes, the exploitation of microbial metabolites has proven to be a significant source for novel metabolites due to the vast diversity of microbes. Microbial endosymbionts are organisms which play a key role in plant physiology and are also characterized for producing potent metabolites. To enhance the rate of searching such anticancer producers, there is simply a need for primary screening. Applications of the Ames test are proposed as primary screening of microbial metabolites and further forwarded for confirmation by simple MTT assay and cytotoxicity assay.