DNA Sequencing FAQs

  1. How should my samples be labeled?
  2. When will I get my results?
  3. When and where do I drop-off my samples?
  4. How much DNA is required for sequencing?
  5. How should I prepare my samples for sequencing service?
  6. Will I get charged if my samples gave little or no readable sequence?
  7. How can I get in touch with the facility?

1. How should my samples be labeled?

Samples should be labeled with your initials and a serial listing. For example, assume your name is Mary Lynch, and you are submitting four samples. Your samples should be labeled ML1 through ML4. The next time you submit samples for sequence analysis, begin with ML5 and continue in this fashion. All tubes must be labeled individually.

2. When will I get my results?

Samples collected by 9:30 am will be posted by 10:00 am the next day.

3. When and where do I drop-off my samples?

Samples can be dropped-off Monday through Friday, between 9:00 am and 5:00 pm in BST L5, Rm 151. Also we have two drop boxes located at Life Sciences Building 2nd floor Room 253 and at CMM (Center for Molecular Medicine) 4th floor Room 450. The drop off time at these two locations is between 9:00 am and 5:00 pm.

4. How much DNA is required for sequencing?

The recommended quantities of Template DNA are shown in the table below:

   
Template Quantity
PCR product:
    100-200 bp
    200-500 bp
    500-1000 bp
    1000-2000 bp
    >2000 bp		  
1-3 ng
3-10 ng
5-20 ng
10-40 ng
40-100 ng
Single-stranded 50-100 ng
Double-stranded (Plasmid DNA) 250-500 ng
Cosmid, BAC 0.5-1.0 µg
Bacterial genomic DNA 2-3 µg
 
Note: In general, higher DNA quantities give higher signal intensities, however, if the quantities above are exceeded problem will occur with sequencing.
Note: The template quantities stated above should work with all primers. The amount of PCR product to us in sequencing will also depend on the length and purity of the PCR product.
 

 5. How should I prepare my samples for sequencing service?

Samples should be submitted in 0.2ml strip tubes.  In the 0.2ml tube combine the following: sample DNA (please refer to the above table for the amount of DNA to use), 3.2pmol primer/sample, PCR water to 8µl. The total volume of each sample should equal 8µl.

6. Will I get charged if my samples gave little or no readable sequence?

Yes, unless the fault is ours; e.g. computer collection glitch or other hardware problem. Several control samples are processed on every run and the results of these standards are posted with your results in the bins outside the lab for you to consult. If you would like to obtain a copy of our control results, please ask one of the faculty members and we would be happy to provide you with a copy. In the event of a facility problem, we will re-run your sample(s) free of charge.

Leading causes of poor or no sequence are:

  • Not adding template or primer
  • Adding too much primer
  • Poor quality template

If you have questions about your data please do not hesitate to contact the core.

 7. How can I get in touch with the facility?

E-mail the facility at: dna_sequencing@stonybrook.edu or call the DNA Sequencing Facility at 631-444-6849 or 444-6406. If no one is available, leave a voicemail and someone will return your call as soon as possible.