About Marker - for PCR (Feb/14/2002 )

If my target DNA is 128 bp. What Marker that I should use? I ever use phageX174/HaeIII with 2.5% agarose but the band's marker are diffuse. Any idea? Thank you.

You should use an another marker : 1kb Dna ladder plus for exemple. Try with a 1.5% agarose gel, your migration will be more fast

Your pcr product is very short.  Yes, 1.5 gel is OK. but let the dye move to the end of the gel for the best resolution but be careful. You might lost your product