what's the difference between sequencing primer and cloning one. - confused (Jul/18/2007 )
Can I use cloning primers to sequence the gene I cloned with these primers? 
Thanks.
you can definitely able to use cloning primer for sequencing. But what is the point of doing so? You are only able to confirm the cloned gene.
By using sequencing primer, you can check it's orientation as well as how good is the ligation. 
Yeah, for sequencing it's usually better to use a different primer than the one you used for cloning. Many vectors have sites for sequencing primers (like M13) a couple of dozen bases away from the cloning site. This is basically because the first ~40bp or so that you sequence usually don't come out very good. The sequencing is not very reliable there. But in case there isn't a primer site in your vector then you'll have either to use your cloning primers or design new ones up- or downstream of your cloning site (depending on what's your purpose).
By using sequencing primer, you can check it's orientation as well as how good is the ligation.
If your cloned fragment isn't too long, you might be lucky and have the sequence generated by using the cloning primer also capture the vector sequence opposite to it. (I would first go for restriction to determine the direction).
If you use the 2 cloning primers and your cloned fragment isn't too long, you will get the entire cloned part sequenced.
the sequencing generally doesn't show you the bases directly after the end of the primer.
Generally it's recommended to take sequencing primer 50 to 100 bases away from the starting point of interest to get a decent chromatogram.
That's why if you want to correcly determine the cloning of your insert and if relevant, the orientation, you need to use an other primer.
Thanks.
you could use the cloning primers for sequencing, but sometimes they don't work efficiently and this might makes things complicated for you. Also you will need a primer to verify the sequence which is upstream of the primer unless there is different primer which would give you this sequence.
Primers are cheap, order a set of primers for sequencing and enjoy sequencing.