NEBNext® Ultra™ II End Repair/dA-Tailing Module


The NEBNext Ultra II End Repair/dA-Tailing Module has been optimized to convert 500 pg-1 μg of fragmented DNA to repaired DNA having 5´ phosphorylated, 3´ dA-tailed ends. The module is optimized for use with the NEBNext Ultra II Ligation Module (NEB #E7595), and is part of the Ultra II workflow which enables high yield preparation of high quality libraries from 500 picograms to 1 microgram of input DNA.

This module is compatible with Illumina workflows and with some Oxford Nanopore MinION workflows.

Functional Validation

Each set of reagents is functionally validated together through construction and sequencing of a transcriptome library and sequenced on a DNA library on the Illumina sequencing platform.

Lot Control

The lots provided are managed separately and qualified by additional functional validation. Individual reagents undergo standard enzyme activity and quality control assays, and also meet stringent criteria in the additional quality controls listed on each individual component page

Reagents Supplied

The following reagents are supplied with this product:

Store at (°C)Concentration
NEBNext Ultra II End Prep Enzyme Mix-20
NEBNext Ultra II End Prep Reaction Buffer-20

Properties and Usage

Storage Temperature



  1. There are 3 NEBNext Ligation modules, the NEBNext Ultra II Ligation Module (#E7595), the NEBNext Ultra Ligation Module (#E7445) and the NEBNext Quick Ligation Module(#E6056). Which module should be used in conjuction with the NEBNext Ultra II End Repair/dA-Tailing Module?
  2. How do I clean up the reaction once complete?
  3. Can I store the reaction after it is finished in the thermocycler (ie when it reaches the 4°C hold)?


  1. Protocol for use with NEBNext® Ultra™ II End Repair/dA-Tailing Module (E7546)


The Product Manual includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name these document files: manual[Catalog Number].

Safety Data Sheet

The following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.