FAQ: What sample types and quality are compatible with the NEBNext UltraExpress™ RNA Library Prep Kit?

The NEBNext UltraExpress RNA Library Prep Kit has been extensively tested using Universal Human Reference RNA, bacterial RNA mix, and RNA extracted from human whole blood, but it is expected to be compatible with a range of sample types with good quality RNA. While successful libraries have been produced using low-quality samples, optimizing adaptor concentration and PCR cycles is necessary to achieve good quality libraries. We do not recommend using <100 ng of low-quality total RNA (e.g., from FFPE samples) with the NEBNext UltraExpress RNA Library Prep Kit. For highly fragmented RNA samples and low-input, low-quality samples, we recommend using the NEBNext® Ultra™ II Directional RNA Library Prep Kit for Illumina® (NEB #E7760/E7765).