Formalin is commonly used as a fixative for the long-term storage of clinically-important tissue samples. After fixation with formalin, the tissue sample is typically embedded in paraffin; the paraffin both promotes tissue preservation and enables tissue sectioning.
While the fixation process adequately preserves the ultrastructure of the tissues, it often results in various types of damage to the DNA within the tissues, including deamination of cytosine to uracil, generation of nicks and gaps, oxidation of bases and blocking of 3´ ends, as well as fragmentation and crosslinking of the DNA. Gathering meaningful biochemical data, including high-quality DNA sequence information, from these samples can thus be challenging. In addition, archived tissue samples can be very small, and may only contain trace amounts of the cells of interest, and therefore the nucleic acid of interest.

As FFPE samples often contain valuable and irreplaceable DNA sequence information, NEB’s scientists called upon the company’s 40-year history in enzymology and reagent development to address the challenge. They developed a novel method to repair the
DNA in FFPE samples ahead of library preparation and sequencing. The NEBNext FFPE DNA Repair Mix is a cocktail of DNA repair enzymes formulated and optimized for the repair of such DNA. The repaired DNA is compatible with any downstream application or sequencing platform.

"We are pleased to add the NEBNext DNA Repair Mix to our growing line of reagents for sample preparation," stated Fiona Stewart, Product Marketing Manager for NEBNext at NEB. "The NEBNext FFPE DNA Repair Mix makes it possible to apply today’s and
tomorrow’s next-generation sequencing (NGS) technologies even to compromised FFPE tissue samples, which we hope will open up new avenues in the analysis of these valuable samples."

NEBNext products are a series of highly pure and cost-effective reagents that facilitate DNA and RNA library preparation for next generation sequencing. The innovative NEBNext product line includes the Ultra™ Library Prep kits for DNA and RNA, which address the increasing need for fast and robust performance, and also allow the use of low-nanogram amounts of input DNA or RNA – ensuring optimal data quality with flexible workflows.

For more information on NEBNext reagents for library preparation, visit NEBNext.com.