Once in solution, the peptide should either be used ASAP or frozen at –80 ºC. Be sure to aliquot the peptide solution into usable portions prior to freezing to avoid the need to freeze-thaw. TAT-HyNic peptide conjugation. A 3–5 mole excess of TAT-HyNic peptide should be used. Purification can be performed with a diafiltration column with a 5 kDa MWCO or by dialysis. Storage buffer should be PBS with 0.5% azide.