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Peptide Solubility and Storage Guidelines:

1.  Calculate the length of the peptide.

2.  Calculate the overall charge of the entire peptide according to the following table:

 ContentsAssign valueAcidic amino acidAsp (D), Glu (E), and the C-terminal -COOH.-1Basic amino acidArg (R), Lys (K), His (H), and the N-terminal -NH2+1Neutral amino acidGly (G), Ala (A), Leu (L), Ile (I), Val (V), Cys (C), Met (M), Thr (T), Ser (S), Phe (F), Tyr (Y), Trp (W), Pro (P), Asn (N), Gln (Q)0

3.  Recommended solution:

Overall charge of peptideDetailsNegative (<0)1.  Try to dissolve the peptide in water first.2.  If water fails, add NH4OH (<50 μL).3.  If the peptide still does not dissolve, add DMSO (50-100 μL) to solubilize the peptide.Positive (>0)1.  Try to dissolve the peptide in water first.2.  If water fails, try dissolving the peptide in a 10%-30% acetic acid solution.3.  If the peptide still does not dissolve, try dissolving the peptide in a small amount of DMSO.Zero (=0)1.  Try to dissolve the peptide in organic solvent (acetonitrile, methanol, etc.) first.2.  For very hydrophobic peptides, try dissolving the peptide in a small amount of DMSO, and then dilute the solution with water to the desired concentration.