Why does the sample with loading solution not sink to the bottom of the wells of an SDS-PAGE?

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Maria Filippa Addis

Hi Neda, did you add glycerol to your loading solution? This is needed to increase the density of your sample.

Another reason can be the presence of high amounts of DNA, this can create a viscous material that floats on top of the wells when you load your sample.

How does the sample look like?

Neda Parchami

Hi Maria,,

No. I did noy add glcerol

ok, this is the recipe for Laemmli buffer:

http://www.bioprotocols.info/molecular_biology/Protein/protein_electrophoresis/sds_sample_loading_buffer.php

you should add a reducing agent (DTT, 2-mercaptoethanol) only if running SDS-PAGE in reducing conditions

If you do not add glycerol your sample will not sink!

Of course, this is if you are making your sample buffer yourself!