size optimum

[chipmonk]

dear all
I am new to both the forum and chip seq.
I am using insect tissue for chip. i will use chip seq (abi solid) to identify transcription factor targets. please tell me about the size most people use. I have heard range of 200-1000. some pprs recommend 250 bp peak. please post all the possible ranges their advantages and disadvantages.
thank you all in advance...

[JohnK]

Why are you interested in peak size? I believe peak sizes will vary depending on your method of calling the peaks? Fragment/sonication size is probably anywhere between and around 120-150 bps, but is a rough estimate.

[snetmcom]

you are fine if your CHiP fragments are anywhere from 100-250bp.

[chipmonk]

thanks

sorry for the misguiding english. I meant the chromatin shearing size and not the readout peaks. people use fragment sizes of 500 bp in chip, so I was not sure if 250 is good enough to effectively detect the transcription factor binding sites with good resolution. Thanks for the advice. please add if there is anymore.
regards