Next-generation sequencing technologies provides deep and precise profiling of genome and transcriptome. GENXMAP, expert in sample preparation, proposes the library preparation for sequencing purpose. The sample preparation process varies depending on the sample type and the purpose of the experiment. Different types of genetic material (DNA or RNA) have different sample preparation processes. On top of that, the different applications of NGS add another dimension. Therefore, there are several questions that need to be asked before the experiment to determine the best methods to optimize the most the library preparation process. The goal of library preparation is to convert the extracted nucleic acids into a format that is appropriate for the sequencing technology fits the most to the purpose of study.