Product Class: Other

1 kb DNA Ladder

This product is available in Quick-Load Purple format - enjoy the convenience of a ready-to-load format. Request a free sample today! 

Product Introduction

  • Size range: 500 bp to 10 kb     
  • Value pricing
  • Supplied with free vial of Gel Loading Dye, Purple (6X), no SDS (NEB #B7025).
  • Easy to identify reference bands
  • Small size suitable for 200 gel lanes; large size suitable for 1000 gel lanes


Catalog # Size Concentration
N3232S 0.2 ml 500 μg/ml
N3232L 1 ml 500 μg/ml

Product Information



A number of proprietary plasmids are digested to completion with appropriate restriction enzymes to yield 10 bands suitable for use as molecular weight standards for agarose gel electrophoresis. The digested DNA includes fragments ranging from 0.5-10.0 kilobases (kb). The 3.0 kb fragment has increased intensity to serve as a reference band. The approximate mass of DNA in each of the bands is provided (assuming a 0.5 μg load) for approximating the mass of DNA in comparably intense samples of similar size.

Comes supplied with 1 vial of Gel Loading Dye, Purple (6X), no SDS.

NEB also offers a Quick-Load version of this ladder with purple dye.

  • Recommended gel percentage range: 0.8-1.2%
  • Optimum separation on 1% 

DNA Ladder
1 kb DNA Ladder visualized by ethidium bromide staining on a 0.8% TAE agarose gel. Mass values are for 0.5 µg/gel lane.

Reagents Supplied

The following reagents are supplied with this product:

Store at (°C) Concentration
Gel Loading Dye, Purple (6X), no SDS 25 6 X
Product Categories:
DNA Markers & Ladders Products
DNA Analysis

Properties and Usage


Effective Size Range

500.0bp to 10,002.0bp

Storage Temperature


Storage Conditions

10 mM Tris-HCl
pH 8.0 @ 25°C


  1. This ladder was not designed for precise quantification of DNA mass but can be used for approximating the mass of DNA in comparably intense samples of similar size.
  2. Due to the limitations of the acrylamide gel technology, one or two extra bands may be visible on the DNA ladders when run on a polyacrylamide gel.
  3. 1X Gel Loading Dye, Purple (6X), no SDS:
    2.5% Ficoll®-400 
    10mM EDTA 
    3.3mM Tris-HCl (pH 8.0@25°C)
    0.02% Dye 1 
    0.001% Dye 2 
  4. We recommend loading 0.5 μg of 1 kb DNA Ladder diluted in sample buffer.
  5. All fragments have a 4-base, 5´ overhangs that can be end labeled using T4 Polynucleotide Kinase (#M0201) or filled-in using DNA Polymerase I, Klenow Fragment (#M0210) (1). Use α-[32P] dATP or α-[32P] dTTP for the fill-in reaction.
  6. 1 kb DNA Ladder is stable for at least 3 months at 4°C.
  7. For long term storage, store at -20°C. If samples need to be diluted, use TE or other buffer of minimal ionic strength.  DNA may denature if diluted in dH20.


  1. Sambrook, J., Fritsch, E.F. and Maniatis, T. (1989). Molecular Cloning: A Laboratory Manual (2nd Ed.). 10.51-10.67.

Faqs & Tech Tips


  1. Why are there extra bands visible on polyacrylamide gels?
  2. What are the overhangs on the DNA ladder fragments? Can I end-label them using the T4 polynucleotide kinase (PNK)? What about the Klenow fragment?
  3. Why are the DNA ladders showing up on my Southern blot? What is the sequence or composition of the ladder bands?
  4. How can I quantify the amount of DNA in each band of a marker?
  5. Can I use GelRed® with the DNA Ladders from NEB?
  6. Can I use Midori Green with the DNA Ladders from NEB?
  7. Can I use SYBR® with the DNA Ladders from NEB?

Tech Tips

To make it ready-to-load, dilute in TE buffer instead of water.

Protocols & Manuals


  1. End-labeling Protocol
  2. Suggested Loading Protocol for DNA Ladders & Markers


The Product Summary Sheet, or Data Card, 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 the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at or fill out the Technical Support Form for appropriate document.)

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Quality & Safety

Quality Assurance Statement

Quality Control tests are performed on each new lot of NEB product to meet the specifications designated for it. Specifications and individual lot data from the tests that are performed for this particular product can be found and downloaded on the Product Specification Sheet, Certificate of Analysis, data card or product manual. Further information regarding NEB product quality can be found here.


The Specification sheet is a document that includes the storage temperature, shelf life and the specifications designated for the product. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]

Certificate Of Analysis

The Certificate of Analysis (COA) is a signed document that includes the storage temperature, expiration date and quality control's for an individual lot. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]_[Lot Number]

Safety DataSheets

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

The supporting documents available for this product can be downloaded below.

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Fragment Mass bp