Diagnostic kit and method for detecting a microorganism in a sample comprising an exogenous colored control

Method for detecting a target microorganism in a sample by extracting nucleic acids from said target microorganism followed by the amplification of a specific nucleic acid of said target microorganism in which the development of extraction and amplification are validated by carrying concomitant of the following steps: a. provision of a container comprising, in the dry state, a colored pH indicator and microorganism control includes a control nucleic acid b. addition, in the liquid state, the sample and extraction reagent having a pH below 7 and obtaining a reaction mixture having extraction color the acid form of colored pH indicator c. treating the reaction mixture extraction to release the nucleic acids present in said reaction mixture extraction, d. mixing an aliquot of said reaction mixture treated with a reagent extraction amplification having a pH above 7 and obtaining a reaction mixture having the amplification color of the base form of the pH indicator, e. nucleic acid amplification control. wherein the extraction of nucleic acids of said target microorganism followed by the amplification of a specific nucleic acid of said target microorganism is performed in or in the same containers as extraction of nucleic acids of the microorganism control and amplification acid nucleic control.