Question

Vitamin B12 was used in a column chromatography experiment as a marker to show when all of the protein had eluted off the column. Will vitamin B12 show up on the SDS-PAGE? Explain.

Answer 1

SDS is Sodium Dodecyl Sulphate & PAGE is PolyAcrylamide Gel Electrophoresis
 One of the common method for separating proteins by electrophoresis using a discontinuous polyacrylamide gel as a support medium and sodium dodecyl sulphate (SDS) to denature the proteins.

 It involves electrophoresis method that allows protein separation by mass.

 Approx. 1.4 grams of SDS bind to 1 gram of protein corresponding to one SDS molecule per two amino acid molecules

 SDS act as a surfactant, covering the proteins’ intrinsic charge and conferring them very similar charge-to-mass ratios.  The intrinsic charges of the proteins are negligible in comparison to the SDS (Sodium Dodecyl Sulphate) loading, and the positive charges are also greatly reduced in the basic pH range of a separating gel. Upon application of a constant electric field, the protein migrate towards the anode, each with a different speed, depending on its mass. This simple procedure allows precise protein separation by mass.
 Vitamin B12 molecule will show up on the SDS-PAGE as it is used to estimate the molecular mass of protein.