Blunting

Blunting is a process by which the single-stranded overhang created by a restriction digest is either "filled in", by the addition of nucleotides on the complementary strand using the overhang as a template for polymerization, or by "chewing back" the overhang, using an exonuclease activity. Vectors and inserts are often "blunted" to allow non-compatible ends to be joined. Sequence information is lost or distorted by doing this, and a detailed understanding of the modification should be sought before performing this procedure. Often, as long as the sequence being altered is not part of a translated region or a critical regulatory element, the consequence of creating blunt ends is negligible. Blunting a region of translated coding sequence, however, usually creates a shift in the reading frame. DNA polymerases, such as the Klenow fragment of DNA Polymerase I and T4 DNA Polymerase are often used to fill in (5´ → 3´) and chew back (3´ → 5´). Removal of a 5' overhang can be accomplished with a nuclease, such as Mung Bean Nuclease.

FAQs for Blunting

Protocols for Blunting

Common Applications of Exonucleases and Endonucleases

NEB provides a list of common applications for our exonucleases and endonucleases.

Properties of Exonucleases and Endonucleases

NEB supplies many nucleases; several characteristics should be considered when choosing the one best suited to your particular research needs.

Legal Information

This product is covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB).

While NEB develops and validates its products for various applications, the use of this product may require the buyer to obtain additional third party intellectual property rights for certain applications.

For more information about commercial rights, please contact NEB's Global Business Development team at gbd@neb.com.

This product is intended for research purposes only. This product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

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    DNA Blunting Tutorial

    The first step in determining how your ends will be blunted is to determine if they are 5´ or 3´ overhangs. This tutorial will teach you how to identify what type of overhang you have, as well as which enzyme will blunt that end, and how.