I have found this paper explains very clearly your question

Liu, Z.J. & Cordes, J.F., 2004. DNA marker technologies and their applications in aquaculture genetics. Aquaculture, 238, pp.1–37.

Hi Sajedah,

1. Please go through this 12-page slide show (about RAPD-PCR) at below link, and then read the attached simple article (see attachment). You will then get a sense of what is RAPD-PCR, and the difference between starndard PCR and RAPD-PCR.

http://www.powershow.com/view/26dd00-NmEyM/RAPD_PCR_powerpoint_ppt_presentation

Hi! 

RAPD primers are decamer (10 mer) the single primer act itself both Forward n Revers. As genome is made up of four components A,G,C,T. They are arbitrarily arranged . So RAPD primers too designed like that there are many series you can by any one of them. I answered many questions on RAPD if you have patience check them under RAPD. 

Both Yen n Yuan had given good ref.s .

Along with that check the following links too

http://www.ncbi.nlm.nih.gov/probe/docs/techrapd/

http://www.bio-link.org/GMP/Rapdlab1.htm

http://en.wikipedia.org/wiki/RAPD

If you google you get very good information. 

Good Luck

Please go to:

Random Amplified Polymorphic DNA (RAPD)

http://www.ncbi.nlm.nih.gov/probe/docs/techrapd/