Phase triangle relationship

In addition to the MAD and SAD methods, there are the traditional isomorphous replacement methods that include multiple isomorphous replacement (MIR), which uses several heavy atom derivatives, and single isomorphous replacement (SIR), which uses only one heavy atom derivative. The underlying principle to all these methods is the phase-triangle relationship. To understand this relationship we shall begin our discussions with the isomorphous replacement method. 

In Figure 2.6(b), the F and associated vectors are shown with the imaginary axis inverted. Figure 2.6(c) uses F+ from Figure 2.6(a) and F from Figure 2.6(b) in order to construct the phase triangle relationship between F+, F and 2F. .. 

FIG. 4 Relationship between the final AOT and protein amounts in the solid phase for several different experiments, using a w/o-ME extractant of 50 or 100 mM AOT (unifilled and filled symbols, respectively), Wg = 20. Proteins (upward-pointing triangles) bovine serum albumin (downward-pointing triangles) a -ch5miotrypsin (diamonds) lysozyme. (Reprinted with permission from Ref. 58.)... 

Because the equilibrium relationship can rarely be expressed algebraically with any convenience, extraction computations must usually be made graphically on a phase diagram. The coordinate scales of equilateral triangles are necessarily... 

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