About adapter on bead for emPCR

[winmicro40]

Hello, I'm a student in Bioinformatics program.
Now, we are discussing about adapters/primers that attached on the beads for amplifying in Molecular biochemistry class.I have some questions about 454 technology as follow:
1.Adapters/primers on each beads are the same or variation?
2.For emPCR step,how 1 DNA fragment can attach per 1 bead?
3.In emPCR kit,how adapters/primers can attach on beads?
(what is the technology that is used to make DNA bead?)

Thank you,for all answers.

[anujgupta]

Dear winmicro40,

1. Primer on each bead is same. Usually it is anti-B adaptor so that B adaptor of the library can bind to it. In case of Lib-A kit of emPCR used for bi-directional amplicon sequencing, two types of DNA beads are used, one as above and the other with anti-A adaptor.

2. 1 DNA fragment attaches to one bead by using optimum library copies per bead (cpb) determined in the titration called SV emPCR.

3. Most probably it is immobilization / adsorption.