What is a protein standard and why do we load it on our gels?
A. A known protein used to monitor degradation during electrophoresis
B. A set of peptides of known size used to estimate sizes of sample proteins on gels
C. A set of peptides at known concentrations used to determine sample concentration
D. A pre-stained peptide used to tell how long to run a gel
Protein standard is also called as protein ladder used to compare the size of protein in our gel. So, correct option is B.
Answer B. A set of peptides of known size used to estimate sizes of sample proteins on gels