Question

For a native page gel, why does BSA have multiple bands (HINT: its not due to contamination)?

For a native page gel, why does lysozyme not appear on the gel (HINT: its not due to size)?

Answer 1

1) BSA shows multiple band on native-PAGE = reason behind this is that the BSA has property to get oligomerize in the  water and depending on the degree of oligomerization (dimer, trimer, tetramer etc.) we see multiple bands on native-PAGE.

2) lysozyme does not appear on native-PAGE = reason behind this observation is that lysozyme in its native state has overall positive charge on it, and hence even if you load it in gel for running it will run in reverse direction. therefore to prepare the llysozyme solution for gel loading we need to use SDS to give it sufficient amount of negative charge to run.