Primers

The ^UCDNA Sequencing Facility provides the following universal primers free of charge:

Primer	Sequence
M13-21	5' GTAAAACGACGGCCAGT 3'
M13R	5' CAGGAAACAGCTATGAC 3'
T7prom	5' TAATACGACTCACTATAGGG 3'
T7term	5' GCTAGTTATTGCTCAGCGG 3'
T3prom	5' ATTAACCCTCACTAAAG 3'
SP6	5' GATTTAGGTGACACTATAG 3'

If you are designing your own primer for sequencing, please be sure that you use a primer design program to avoid multiple annealing sites, primer-dimer, etc. Be aware that PCR primers do not always work for sequencing since cycle sequencing is a much more stringent protocol than PCR. Please see our FAQ page for more details. Here are some quidelines when designing your own primer for sequencing:

• Primers should be at least 18 bases long to ensure good hybridization with template DNA.
• Avoid runs of identical nucleotides, especially runs of 4 or more G's.
• The G/C content should be in the range of 30-80%, preferably between 50-55%.
• For cycle sequencing reactions, primers with Tm between 50-70 degrees C produce better results than primers outside of this range.
• For primers with G/C content less than 50%, it may be necessary to extend the primer sequence beyond 18 bases to keep the Tm high enough.
• Avoid primers that can hybridize to form dimers.
• Avoid palindromes because they can form secondary structures.
• Primers should be desalted and purified to industry standards.