Dear Gizie Abeje

You did not mention the size of your expected DNA in sample and the size range of your DNA ladder. Ideally your expected DNA band should lie on between the bands of DNA ladder. I would recommend you to check the following:

• Use 1X TAE or TBE buffer for the formation of agarose gel.

• You probably used 2% agarose powder, it is used for small sized DNA sequence such as small PCR product, RT-PCR product in the range of ~100-250 base pairs. So you can lower the agarose percentage in your gel. Make it 1%-1.5% and run the gel.

• Try to run for longer time at lower voltage, if possible.

Otherwise your gel looks okay, except for some smearing bands. DNA sample containing high concentration of salt/degraded sample/contaminated with protein or RNA may give rise to smearing.

Best wishes for your future success.

Dear Satyendra Mondal ,

To let you know,

• I am using 100bp Plus II DNA Marker which is 500bP band reference from 100-15K.
• I tried it even at 1% TAE buffer solution, but this is totally found to be not good for my samples. As you can see on the attached image, the samples are looking better except the marker ladder.
• I run the electrophorosis at 80V for 30-45min.

Dear Gizie Abeje

Thank you for the information. Here are some tips for you.

• You can use 1%-1.5% agarose gel for better resolution.
• Use freshly prepared TAE/TBE buffer. Also, avoid reusing the old gel construct.
• Try to use new DNA ladder, if this DNA ladder is too old.
• Considering the condition of your DNA ladder all right, the reference band at 500 bp looks stretched, so it was not resolved properly. Then it might have occurred due to running of the gel for shorter time. I would suggest you to run for longer time, at 80-100 V for almost one hour.

Best wishes.

Dear Satyendra Mondal ,

Thank you for your suggestions.

Today I tried to see by changing;

• a new marker
• TAE buffer (2%) and
• Voltage ( from 80V=>120 V for 15-20min).

Still the marker bands are not clearly and separately seen. Its a bit tough!

I will try the other options!

With regards,

Dear Gizie Abeje

I think your DNA ladder is okay. You can run it for longer time for the better resolution. At 120 V for 30-35 minutes.

Best wishes.

Dear Satyendra Mondal ,

Many thanks for your valuable suggestions. Your are the only person shared your ideas. The rest are I think keeping their physical distance # COVID-19. I wish you a better health and full protection from the dreaded COVID-19.

Now its ok! The problem was the shortage of running time and Voltage.

Best regards,