The Colorimetric LAMP Mix has been extensively tested for stability and it is very stable and robust under standard handling and usage condition. It contains low concentration of Tris pH 8.1 and the pH-sensitive Phenol Red shows bright pink color around this pH. After repeated usage of the same tube, a slight drop of pH is possible but without noticeable color change or effects on the reaction performance. However, if the 2X Master Mix, especially in nearly empty tubes, is exposed to air after an extended time, its pH may drop to below pH 7, and the Phenol Red would indicate a light orange to yellow color. This change of color provides a visual indication that the solution is no longer suitable for the pH-LAMP reaction. Thus it is recommended to avoid extended exposure to air by closing tube caps and storing small volume of Master Mix solution at -20 °C.