This document discusses forming a ternary mixture of 3 proteins that cannot be separated using cation exchange, anion exchange, hydrophobic interaction chromatography, or size exclusion chromatography. The proteins that could be selected are: bovine serum albumin, a-chymotrypsin, a-chymotrypsinogen, cytochrome C, ferritin, hemoglobin, a-lactalbumin, lactoperoxidase, myoglobin, and ribonuclease A.