In an analysis using two-dimensional gel electrophoresis of the proteins expressed in different cell types, the number of spots that are different in different cells usually exceeds the number of common spots, and even the common spots can still have different intensities. the spots representing which of the following proteins would you expect to be among the common spots when compared across several cell types?
a. rpl10 (a ribosomal protein)
b. hba1 (a hemoglobin subunit)
c. insulin (a hormone)
d. tyrosine aminotransferase (a metabolic enzyme)
e. all of the above