We currently run all samples submitted to the Low Throughput Lab (LTL) on our ABI 3700 using dye terminator chemistry.  You can expect to receive between 400 and 800 high quality bases

 

We will run all samples submitted one time.  We will rerun some sequence reactions that, for unknown or unapparent reasons, produce short reads or an unusual number of ambiguous base calls that we think we can improve by running the sequence reaction again.  We will also repeat sequence reactions that appear to completely fail on the first run.  These reactions produce few (<100 High Quality Bases) and it is unknown if the reaction failure was due to an error setting up the reaction or a primer-template problem.  Please do not expect us to rerun samples submitted to us when: the template concentration was too low, the volume of the sample submitted prevented us from measuring the template concentration and then setting up the sequence reactions properly or your samples contained enough ethanol to inhibit the sequence reaction.

 

Template Concentration:

 

Template concentration should equal or exceed 100 ng/ul.  We can get good sequence from less concentrated samples, but there is more variability.  There are no guarantees we can sequence samples that measure less than 50 ng/ul.  Samples that are submitted at less than 50 ng/ul will be amplified and then run one time.  Expect shorter read lengths (350 – 600 HQB) and less overall quality in these amplified plasmids. 

 

We use 2 ul of each sample submitted to measure the template concentration on our fluorometer.  In general, the DNA concentrations measured on our fluorometer have been approximately 40% less than the concentrations measured by our users who determine [template] on a spectrophotometer.  So adjust your estimates accordingly.  Unless you have submitted enough samples to make specific adjustments of your own, subtract 40% from your OD readings. 

 

How much template is needed?  Plasmids

 

Length of vector (base pairs) + Length of insert (base pairs) X 0.1 =

Nanograms of template needed for each sequence reaction

Divide the total number of bases (plasmid + insert) by 10 to give the nanogram amount of template needed for each sequence reaction.  Multiply by the number of primers you are using and then double it.  If we have 2x the amount of template necessary, reruns can be set up for the next sequencer run and turn-around time for your sequence is significantly reduced.  We also use 2 ul of each sample to check the concentration on the fluorometer, so plan accordingly.  We will keep your unused templates and primers for 3 months.  After 3 months they will be discarded.

 

 


How much template is needed?  PCR Products

 

Length of fragment (base pairs) X 0.1 = Nanograms of template / reaction

Divide the total number of bases in your fragment by 10 to give the nanogram amount of template needed for each sequence reaction.  Multiply by the number of primers you are using and then double it.  If we have 2x the amount of template necessary, reruns can be set up for the next run and turn-around time for your sequence is significantly reduced.  We also use 2 ul of each sample to check the concentration on the fluorometer, so plan accordingly.

 

How much template is needed?  Cosmids and BACs

 

The more template you provide the better the results will be.  We will need 1.0 to 3.0 ugms of template per sequence reaction.  We will bill you double the cost of plasmid/PCR sequencing for cosmids and BACs.  See us before you get started. 

 

 

Custom Primers

Please submit all custom primers between 5.0 and 10.0 uM. We will use 1.0 to 2.0 ul / reaction.  Melting temperature of these primers should be between 45 and 600C. 

 

 

Would you like to get your DNA sequence without a mini-prep?

 

Get DNA sequence from bacterial cells in liquid culture or from colonies picked from agar plates.

 

Bring 5 to 10 micro liters of a saturated bacterial culture grown in LB media supplemented with the appropriate antibiotic.  Please, submit cultures grown in LB media only.  “Extremely rich growth media” may interfere with the amplification phase of this procedure.

 

OR

 

A small amount of material from a colony may be picked from an agar plate, resuspended in 20 micro liters of sterile TE (10 mM Tris, 1 mM EDTA, pH 8.5) and then submit to the LTL for sequencing.  Please be careful and not transfer any agar with the colony. 

 

OR

 

If the clones are required for further use:

 

Pick a colony from an agar plate and resuspend it in 20 micro liters of sterile LB supplemented with the appropriate antibiotic.  Submit 5 micro liters to the LTL.  Please be careful and not transfer any agar with the colony.