How can I get better separation of my bands?
First check the percentage of your agarose gel. A higher percentage will help you to resolve smaller molecular weights while a lower percentage will help you to resolve larger molecular weights.
Find additional tips, troubleshooting help, and resources within our Nucleic Acid Purification and Analysis Support Center.
How much DNA can I load for my E-Gel Agarose Gels?
To determine the amount of DNA to load per well for your specific E-Gel agarose gel, please refer to the table on page 14 of the E-Gel Power Snap Electrophoresis System user guide (https://assets.thermofisher.com/TFS-Assets/LSG/manuals/MAN0017050_egel_powersnapsystem_UG.pdf).
Find additional tips, troubleshooting help, and resources within our Nucleic Acid Purification and Analysis Support Center.
What does intact RNA look like when run on an agarose gel?
Intact RNA should have a 2:1 ratio of 28S:18S bands. You may see a smear of RNA that extends from <9 kb to 0.5 kb, indicating the presence of mRNA in the sample. To see an image or to read more about RNA assessment, visit this website (https://www.thermofisher.com/us/en/home/references/protocols/nucleic-acid-purification-and-analysis/rna-protocol/agarose-gel-electrophoresis-of-rna.html).
Find additional tips, troubleshooting help, and resources within our Nucleic Acid Purification and Analysis Support Center.
How can I perform RNA electrophoresis?
For nondenaturing RNA electrophoresis, we recommend using our E-Gel Precast Agarose Gels. Please note that E-Gel Agarose Gels are not validated to be RNAse-free. However, many of our customers routinely use E-Gel Agarose Gels for RNA analysis with success. If RNA is run on an E-Gel Agarose Gel, any loading buffer that would be used for nondenaturing RNA electrophoresis should be fine.
For denaturing RNA electrophoresis, there are several denaturing agents to choose from, including formaldehyde, glyoxal, formamide, and methyl mercury. Denaturing conditions disrupt hydrogen bonding so that RNA runs without secondary structure, as single-stranded molecules.
For denaturing RNA electrophoresis, our E-Gel EX Agarose Gels can be used. The only denaturing agent that is compatible with the E-Gel EX system is formamide, 50-90%. Using other denaturing agents will result in poor band separation and morphology. Please note that we do not recommend running samples prepared in RNA loading buffer on the same gel with samples prepared in water. Please see below for the RNA loading buffer recipe and denaturing electrophoresis conditions:
RNA Loading Buffer:
Deionized formamide: 200 µL
10X MOPS-EDTA-Sodium Acetate Buffer (0.4 M MOPS, pH 7.0, 0.1 M sodium acetate, 10 mM EDTA): 40 µL
Deionized formaldehyde: 76 µL
Water: 14 µL
Denaturing Electrophoresis Conditions:
1. Mix 15 µL of RNA loading buffer with 1-5 µL of RNA (1-5 µg).
2. Heat samples at 65 degrees C for 10 min to denature RNA.
3. Place samples on ice immediately after heating.
4. Load entire sample onto an E-Gel EX agarose gel.
5. Electrophorese for 30 minutes.
For denaturing RNA electrophoresis under formaldehyde-free conditions, we recommend using our NorthernMax-Gly Kit (Cat. No. AM1946). With this kit, RNA samples are denatured in glyoxal/DMSO loading buffer and run on a glyoxal-containing agarose gel.
Find additional tips, troubleshooting help, and resources within our Nucleic Acid Purification and Analysis Support Center.
Should I use agarose or polyacrylamide gels for DNA electrophoresis?
Agarose is commonly used as it is nontoxic, easy to use, and offers a broad range of separation. We offer precast E-Gel Agarose Gels or reagents to pour your own agarose gels. Polyacrylamide gels are typically used for high resolution of DNA molecules that range in size from 10-3,000 bp. We offer precast Invitrogen TBE polyacrylamide gels and UltraPure reagents.
Find additional tips, troubleshooting help, and resources within our Nucleic Acid Purification and Analysis Support Center.
