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All gradient samples give bands! How come? - (Jul/11/2009 )

I just received new primers so i ran a gradient PCR to determine best annealing temp.

surprisingly all of my 5 tubes give the correct band.

temps were 57, 59, 61, 63 and 65C.

the only problem is that I have a lot of smear above the bands,....but nothing below it or no primer dimer

-Curtis-

Its Okay

The smear could be coz of high template, just cut yr band of interest and proceed.

Best,
TC

Curtis on Jul 11 2009, 08:43 PM said:

I just received new primers so i ran a gradient PCR to determine best annealing temp.

surprisingly all of my 5 tubes give the correct band.

temps were 57, 59, 61, 63 and 65C.

the only problem is that I have a lot of smear above the bands,....but nothing below it or no primer dimer

-T C-

The one that gives the brightest band is the one with the good annealing temperature. your purpose is to find the optimal annealing temperature right?

-jiajia1987-

Try reducing the amount of DNA you're using

do 1:10 and 1:100.

see if it helps

-hanming86-

Curtis on Jul 11 2009, 11:13 PM said:

I just received new primers so i ran a gradient PCR to determine best annealing temp.

surprisingly all of my 5 tubes give the correct band.

temps were 57, 59, 61, 63 and 65C.

the only problem is that I have a lot of smear above the bands,....but nothing below it or no primer dimer


This happen to me before. what I do was reduce the annealing time and extension time, and the smear gone, at least it works for me.

Hope you are not running a "rush" electrophoresis (160w ??)...this might make the smear on top happen too...for my experience.

-adrian kohsf-