Guanidine Isothiocyanate UltraPure™ Guanidine Isothiocyanate is a strong protein denaturant when used at high concentrations. It is useful in the isolation of intact RNA from sources rich in RNase such as pancreas (1). Form: Powder Product Size: 500 g Reagent Type: Guanidine Isothiocyanate Shipping Condition: Room Temperature Regulatory Statement: For Research Use Only. Not for use in diagnostic procedures. Store at room temperature.