The mnemonic to remember blotting techniques is “SNoW DRoP”
S - Southern - DNA - D
N - Northern - RNA - R
O - Oooooo - Ooooo - O
W - Western - Protein - P
Hope you won’t go, “Which direction was that again?” in the exam =P
There’s another simpler one for all those who can speak the language Hindi.. Southern in Hindi is Dakshin for DNA & Western in Hindi is Paschim for Protein!
If you want to visualize DNA at replication level, you will use Southern blot. This will require a DNA probe attached to phosphate.
RNA at transcription level can be visualized with Northern blot.
This will require a DNA probe attached to phosphate too.
Remember: If you want to visualize protein at transcription level, you will go with Northern blot!
Proteins at translation level are just antigens (Whether they are cell membrane, cytoplasmic or secretory proteins!) Therefore, antibodies (not probes) are used to visualize proteins by Western blot.
DNA binding proteins also known as transcription factors go to the nucleus and bind to DNA. They are proteins but they work at the DNA level. They are different than just regular antigens and therefore, we use DNA probe (not antibodies!) to visualize them. This is known as the South Western blot :)
Thought of adding this simple little side note that the mnemonic doesn’t include!
Hope you all are doing awesome! <3