Hi Tarana,

Standard protocol here in our lab is to prepare a stock solution of DHE at 5 mM in anhydrous DMSO. The use concentration is 30 micromolar. It can be decreased down to 20 micromolar.

Two frequently encountered pitfalls are:

1) DMSO derived autooxidation products (such as formaldehyde, methyl mercaptan etc.) are very dommageable to any DHE applications (and others). DMSO should be of the highest grade available and kept at -20°C.

2) DHE solutions also can spontaneously oxidized. It should appear slightly pink in color, a more intense color such as purple may be indicative of autooxidation of the dye. 

Best regards and good luck for your experiments

Philippe Urban

Thanks Philippe, your answer was indeed helpful.

Has anyone used the DHE solution already stabilized in DMSO (# D23107 invitrogen) for drosophila tissue staining?