We go for boiling method with 5 ml culture and it works very well.

Pellet down the 5 mL cell culture,

resuspend it in 200ul nuclease free water

and heat it at boilng temperature for 15 min,

Centrifuge and use the supernatant.

Good luck.  

Hi Ibrahim

The boiling method consider a good method as describe by Gaurav

Best regrades

As Gaurav Kumar Singh said, boiling is faster and easyer, you could even go for sonication (as below). But I'd rather boiling method...

http://www.biotechniques.com/multimedia/archive/00004/BTN_A_05395BM02_O_4851a.pdf

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC139681/

Article Improved protocol for recovery of bacterial DNA from water f...

Use boiling method or commercial DNA extraction kit.

I use  boiling method or commercial DNA extraction kit. too. Both experience are good but Boiling method is more easy .   

Thanks for your answers.

can i get the protocol for boiling method .. thanks