Product Class: Vector


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Catalog #SizeConcentration
N3021S30 μg1,000 μg/ml
N3021L150 μg1,000 μg/ml


This is the double-stranded, covalently closed, circular form of ΦX174 RF I DNA (supercoiled). The molecular weight of ΦX174 RF I is 3.50 x 106 daltons and it is 5,386 base pairs in length. The vast majority of the molecules are RF I, and the remainder are RF II, as determined by agarose gel electrophoresis.

DNASU and Addgene are central repositories for plasmid clones and collections that may also be helpful.

Peptide Sequence

The ΦX174 RF I DNA is isolated from E. coli HF 4704 infected with ΦX174 am3 cs70 by a modification of the method of Godson and Vapnek (nucleotide sequenced by F. Sanger).

Properties and Usage

Affinity Tag


Storage Temperature


Storage Conditions

10 mM Tris-HCl
pH 8.0 @ 25°C

Supporting Documents

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


  1. Sanger, F. et al. (1978). J. Mol. Biol.. 125, 225-246.
  2. Godson, G.N. and Vapnek, D. (1973). Biochem. Biophys. Acta. 299, 516.
  1. How homogeneous is the DNA/ how much is supercoiled?
  2. Are the plasmids cesium purified?