An Introduction to the DNA Sequencing Core Sanger Sequencing Service

The DNA Sequencing Core provides University of Michigan investigators access to high-quality automated Sanger DNA Sequencing technology on a recharge basis. The cost of this service compares favorably with similar cores at other institutions, as does the quality of the data obtained. Turnaround time is very short; results are usually returned by email within 48 hours of sample submission. This document provides basic information needed by prospective clients of the Core.

Description of Service

The Core accepts DNA samples (pure plasmids, mini-prep plasmids, M13 clones, cosmids, lambda clones, PCR products, gel isolated fragments, bacterial genomic) and processes them according to protocols for Applied Biosystems DNA Sequencers (Model 3730 XL sequencer). One sequencing run (one template, one primer) typically produces 900 nucleotides of high-quality sequence data or more, for good-quality template and a well-designed primer. The results are returned in two forms: a raw sequence file and a chromatogram file. The sequence file (a flat ASCII text file) is returned to the researcher by electronic mail. The chromatogram file is available on our data server (password protected to prevent unauthorized distribution of your data).

Standard Primers Provided

The Core provides five standard primers free of charge: T7, T3, SP6, M13FORW and M13REV. Please see the table of primers and their sequence for reference. We will also sequence using custom primers submitted by the individual investigators. See Design of Primers for Automated Sequencing for suggestions on how to design your own primers.

Controls Included

Each sequencing gel includes at least one lane of standard DNA known to generate good sequence. In addition, if any of the customers' samples utilize one of the Core's five standard primers, we will also include a positive control lane for that primer. The gel, sample handling and data analysis are extremely reliable and the Core personnel have a very low rate of error. If any problems are indicated in our sample processing, we repeat the affected samples free of charge.

Turnaround Time

We typically process samples within two business days after receipt. Check the current backlog for up-to-date turnaround information. Samples are processed Monday through Friday for overnight instrument runs. Processing typically begins between 6:00 and 10:00 on that day's reactions, and the gels are loaded into the sequencers for their overnight run at about 4:00 PM. The data are processed the following day and returned by email to the customers, usually between 11:00 AM and 4:00 PM. Some additional notes:

  • If the current backlog is more than 2 business days, you may wish to consider requesting Rush Processing
  • If we have no backlog, you may get the faster turnaround time by bringing the samples to the core before 9:00 AM so they may be selected for that day's processing. We cannot guarantee this, however, unless you request RUSH service.
  • In the event the numbers of samples exceeds our ability to process them, on-campus investigators take precedence over off-campus clients, and bulk-rate samples (96-well plates) take lower priority than normal samples.