Plasmids 101: How to Name Your Plasmid in 3 Easy Steps

There are no universal rules for naming plasmids but here are some good guidelines to follow in order to ensure that people can quickly and easily identify what your plasmid contains and other important information.

Tip: A lowercase "p" is often used as the first letter of a plasmid name and simply denotes that the object is a ‘plasmid’. “p” is for plasmid.

pXXXXX-XXXX

Step 1: Backbone name

Include the empty backbone name in your plasmid name. This simple piece of information can often convey many important details. Once you know the backbone a plasmid is based on, you can usually derive: a) the bacterial antibiotic resistance, b) the promoter that drives the insert, and c) any other selection markers (for use in other cell types, e.g. eukaryotic cells).

pBACKBONE-XXXXX

Tip: For a catalog of published and commercially available empty backbones, visit Vector Database.

Step 2: Insert name 

Include information about the insert in your plasmid name. This is often a 3-6 letter representation of the gene (or DNA sequence).

pBACKBONE-hGene

Tip: Often researchers will add a lower case letter to the beginning of their insert abbreviation to specify what species it is. Example: ‘h’ is for Human (homo sapiens), ‘m’ is for mouse (mus musculus), ‘r’ is for rat (rattus rattus or rattus norvegicus), etc.

Step 3: Add your tags 

Add any tags or fusions that are on your insert. Typically you would list any tag or fusion protein in the order they appear in the plasmid and their relative position to the insert. Example, if you have a Flag tag on the N-terminal of your insert, you would list it first.

pBACKBONE-Flag-hGene

If there was also an EGFP fused to the C-terminal of your insert you would list it after the insert.

pBACKBONE-Flag-hGene-EGFP

Other considerations 

If your insert contains a mutation or modification, this should be included in the plasmid name. Mutations are generally listed as the amino acid change and not a nucleotide change. The proper way to denote an amino acid mutation is to list the one letter abbreviation of the wild type amino acid immediately followed by its position (number) relative to the start Methionine (Met) followed by the one letter abbreviation of the mutated amino acid currently at that position.

In contrast, unmutated or Wild Type (wt) versions of the insert are often denoted by "wt" either directly before or directly after the insert name.  

Example: If the Glutamine at position 295 was mutated to an Alanine, Q295A. 

Mutant version: pBACKBONE-Flag-hGene(Q295A)-EGFP 

Wildtype version: pBACKBONE-Flag-hGene-EGFP or pBACKBONE-Flag-hGene(wt)-EGFP

These simple rules allow any scientist to know what is in a plasmid and often how it can be used just by reading the name. For more information about plasmid features and tips you can use in the lab, check out more posts in our Plasmids 101 series.

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