Services | DNA Sequencing | EST Sequencing

EST SequencingExpressed Sequence Tags (ESTs) can be used for a number of purposes ranging from identification of novel genes, to transcript profiling. These cDNA clones represent expressed mRNA transcripts from various libraries. As ESTs are often purchased as cDNA plasmid clones, it is important to evaluate their integrity prior to utilizing them for one’s research goals. MRC PPU DNA Sequencing and Services is happy to help with this process from start to finish.

Our facility can assist those customers who need to obtain sequence information from EST clones that they have, but who would rather not have to grow these up and then mini-prep them. Upon receipt of the culture (usually an agar stab) from you, we will streak this on an agar plate, pick four independent colonies into LB broth and grow them overnight. We will then mini-prep DNA from these colonies using our Qiagen Bio-Robots. 

We can then quantitate your DNA and sequence up to two of the constructs from either a single end (please tell us which end you wish us to sequence from) or both ends depending on the option you chose. You will be provided with the agar plate (if you want it), the original EST, the DNA mini-preps and your sequence(s).

We encourage you to review the information below prior to submission so that your EST submission has the potential to yield the most robust information for your studies.


Materials Required Per Reaction

Expressed Sequence Tag (EST)

  • We ask that customers please provide us with your EST (as it arrives from the supplier) plus its database entry

Primer: 3.2 pmole (Please send a minimum of 10µl of 3.2 uM primer stock to avoid issues associated with evaporation)

  • Please note that this amount refers to custom primers which can be sent to us by the customers
    • If you would like our facility to synthesize primers for your EST Sequencing, we can do so as well. Learn more about our Custom Primer Synthesis
  • Standard Primers are available for free from our facility. A complete list of these is available on our Standard Primers page


When submitting your sample, you will be able to choose from:


If your EST requires a primer not listed in our standard set, we request that customers please either supply the primer themselves, or identify the sequence and request MRC PPU DNA Sequencing and Services to proceed with custom primer synthesis.

Special Considerations

Read Length

There are many factors that can affect the read length one obtains. Our facility will endeavour to provide customers with the longest read possible depending on service requested. Our new ABI 3730 sequencer uses the latest technology and provides really excellent results. Please remember that ESTs are cDNA clones and, therefore, usually have poly A tails – which can sometimes adversely affect sequencing reactions.

With a template of appropriate quality, customers can expect read lengths of up to 1000 bases of sequence from a single primer when sequencing standard templates (<20kb). For other types of template (especially for large templates), read lengths can decrease to issues of template quality and quantity. If you have problems achieving good read lengths with high quality template, please take a look at our resources section. If you still need more help, please feel free to contact us.

Upon receipt of your sequencing results, if you identify that your sequence contains a long poly(A) tail (greater than about 20 adenine nucleotides), then it is quite possible that the sequence after the poly (A) tail will be poor/unreadable. We apologise for this, but this is a feature of the chemistry used. Fortunately, there is a method that can help – please contact us for more details. 


STANDARD EST SEQUENCES:  If all your templates are of a similar composition (<20kb and do NOT contain secondary structure/high GC-content) each EST can be processed for the following costs:

Sequencing in ONE Direction EST Sequencing in TWO Directions
£40 £45
  • Processing of ESTs includes:
    • Streaking of colonies
    • Isolation of 4 colonies
    • Extraction of 4 colonies/mini-prep growth
    • Sequencing of up to 2 separate colonies


FOR PLASMIDS WITH HIGH GC-CONTENT:  If all your templates are of a similar composition (<20kb, containing secondary structure/high GC-content) each EST can be processed at the costs indicated below. This is due to the fact that an 'Augmented Protocol' will be used for plasmids known to contain secondary structure/high GC-content.

Sequencing in ONE Direction EST Sequencing in TWO Directions
£41 £46
  • Processing of ESTs includes:
    • Streaking of colonies
    • Isolation of 4 colonies
    • Extraction of 4 colonies/mini-prep growth
    • Sequencing of up to 2 separate colonies


Do you routinely require a large number of ESTs processed?

Why not contact our staff to learn about savings options?

Our pre-payment option will help you save more per EST!


  • Standard primers offered by MRC PPU DNA Sequencing & Services are free!
  • Custom primer synthesis prices will reflect the size of the primer – the cost to the customer is £0.50 per base

Learn more about all our pricing and turnaround.

Please note that prices are exclusive of VAT, which customers outside The University of Dundee will be charged at the appropriate rate (currently 20%) on all products and that all sales are subject to MRC PPU DNA Sequencing and Services' Terms and Conditions.

Turnaround Time

Turnaround time for this option will be highly dependent on receipt of a customer’s EST clone. We can routinely provide sequence information of ESTs (utilizing standard primers) within 4 working days of receipt of the clone from customers.  


Shipping Details

  • Labels
    • Please ensure that samples are clearly labelled so that we can identify them.
  • Packing Materials
    • Test Tubes/Agar Culture Stabs
      • Please also ensure that your samples are well protected and packaged to meet Post-Office or courier regulations


Postage Costs

  • Customers are responsible for paying all postage / carriage charges
    • For DNA samples or agar plates, normal first class post should be sufficient
      • As this does not always arrive as "next day post", we recommend that customers who have deadlines to meet send their samples by a guaranteed next day delivery service
  • Insufficient postage provided on a package will cause a delay in use receiving the package
    • If MRC PPU DNA Sequencing and Services is then charged upon receipt, please note that we will need to pass this cost onto the customer


Postal Address:

DNA Sequencing and Services
Medical Sciences Institute
School of Life Sciences
University of Dundee


(01382) 388019


(01382) 388729


Do you need any help? Please get in touch and we’ll be happy to lend a hand.