At Addgene, we sequence all incoming plasmids using Next Generation Sequencing (NGS). While our QC NGS processes have changed over the years, each full plasmid sequence is verified prior to the plasmid being made available for distribution to other researchers.
In 2026, Addgene transitioned the QC sequencing of most plasmids to Plasmidsaurus, a pioneer of whole plasmid sequencing. Plasmidsaurus utilizes Oxford Nanopore Technology (ONT) long-read sequencing and an automated custom analysis pipeline, resulting in a basecall accuracy of 99.9999%. For plasmids deposited prior to 2026, plexWell library preparation technology provided by seqWell coupled with Illumina sequencing was used to sequence and assemble full plasmid sequences.
Addgene scientists analyze the NGS results to validate the identity of important plasmid elements including the insert, essential backbone features, any mutations indicated during the deposit process (such as mismatches, truncations, and insertions), and the frame of tags or fusion proteins. Addgene also aligns the NGS results with any full or partial sequences provided by the depositing lab.
Full plasmid sequence data can be found from the Sequences link on each plasmid webpage under the heading Addgene-Verified Full Sequences. If NGS cannot assemble a full plasmid sequence, but provides useful data, Addgene will make this available as a partial sequence under the heading Addgene-Verified Partial Sequences. This section may also include any partial Sanger sequence verification that has been performed on the plasmid. For each sequencing result, the source of the data is indicated in the sequence header:
- Addgene NGS Result: generated by next-generation sequencing at Addgene
- Plasmidsaurus Whole Plasmid Sequence: generated by Whole Plasmid Sequencing at Plasmidsaurus
- Assembled Sequence: built from reference sequence(s) and/or Sanger reads
- Primer name and sequence: Primer used for partial Sanger sequence verification
If during validation of a plasmid you identify a sequence discrepancy relative to the provided sequences, please report this problem to our Scientific Applications Team and they would be happy to assist.