Table II Comparing postnormalization protein quantities for experiments that that were combined by optical density (A and B) or protein concentration (E and F)
CategoryConditionNo. of proteinsCorrelation
1Both proteins FCa > 1.5 in the same directionb37Positive
2One protein FC > 1.5 and FC < 1.5 in the other protein, both in the same direction101Positive
3Both proteins FC < 1.5 in the same direction272Positive
4Both proteins FC < 1.5 in different directions145Uncertain
5Both proteins FC > 1.5 in different directions52Negative
  • a FC is expressed as a 14N:15N value.

  • b Direction refers to the relative increased abundance of proteins toward either the 14N or 15N label.