if the quality of the sequencing is otherwise good can you not just change the scale of the X axis on the electropherogram. Can you post an electropherogram for us to see?

or it can sometimes be associated with poor filling of the capillary or sample overloading so you could try loading less sample ( shorter loading time,lowere loading voltage or just a slightly more dilute sample

Have you checked the quality/age/expire date of your gels? Old gels can give such large peaks. So please refill with fresh gels and try.

Rgds

Dear Sir,

Thank you very mcuh for your advises. Yes, quality is good and raw data is fine. I will follow your guild lines and update you. This problem stated recently. I checked with new reagent kits also.

thank you

Dear chamila,

When I say "gel" I mean Polymer. Usually when the polymer is not fresh (is outdated or not well conserved) it gives such irregular peak width. Then we spend a lot of time changing many other parameters for nothing.

Good luck