pyrosequencing...

[fibonacci]

have anybody here know about 454 pyrosequencing???

is it much better than Sanger method???? :confused:

[CharonY]

Yes I do. It has its advantages as employed in the 454 system. Main advantage is the the huge amount of reads per run (~ 20 megabases), and the resulting low cost per base.

Main disadvantages compared to the Sanger method are the short reads (> 100 bp), though a next generation model should be able to double the current system. The latter limits the utilization of 454 for sequencing of complete novel genomes a bit. Most of the time you need a scaffold (already sequenced organism, or a library) to reconstruct the genome.

 

Other sequencers exit that can sequence ~ 1Gbase per run (Solexa) with even shorter reads (~20bp), for specialized applications (clearly not genome sequencig).

Currently a variation of the Sanger sequencer (with immobilized polymerases) is under development, combining long reads with a large number of parallel reads.

Unfortunately I probably cannot afford that one.

[Bluenoise]

Unfortunately I probably cannot afford that one.

 

Yeah... ...also unless you do a massive amount of sequencing is far more affordable to just outsource it. (Not to say that you don't do a large amount of sequencing of course)

 

We have two fairly new sequencers in our lab just sitting around gathering dust. It's just not worth the time, effort, and resources to do it ourselves when we can send it down the hall for $8 a run. Though it would be quicker to do it myself.

[CharonY]

Well, most commercial sequencing services are massively cheaper than academic ones. However, to date few are offering 454 sequencing. In my old workplace they bought a 454 to sequence a vast number of genomes, which are related to known ones. The price tag here is, of course nothing a traditional sequencing service can compete with.