Dear Christina,

Thanks a lot for your suggestion. I am not sure whether  the blurry deposition is outside or inside root tip. I am also not sure whether the deposition is DNA. May be its one of the character of old root tip. I will try reducing PI concentration and increasing staining time.

Thanks again

Hi Rupak,

If the roots become 'fat' you may have problems with the laser penetrating the sample and also the fluorescence being scattered as it emerges. It may be that the PI did reach the inner cells but you are not exciting it efficiently or detecting the fluorescence.

If this is the problem you would typically need to either section the material or use a multi-photon confocal microscope which can image in much thicker samples.

Dear Matthew J Gratian,

Thank you very much for your suggestions. I also think that laser didnot penetrate well inside 'fat' old root tips. I will try multi-photon confocal microscopy.

Thanks again.