I have been trying to produce the malachite green-ammonium molybdate solution for a standard malachite green ATPase assay, and I have only been able to produce what I'm told is the right color (orange/clear) solution once out of many attempts. I have prepared the solution by dissolving 17 mg malachite green in 37.5 mL MQ H2O and combining that with a solution made up of 525 mg ammonium molybdate tetrahydrate in 4N HCl. This has resulted in a dark greenish-orange solution in all but one instance.
Has anyone else had this problem in the past, and, if so, how did you overcome it? I have tried using MQ water from other sources to rule that out as a possible contaminant to no avail. The malachite green and ammonium molybdate tetrahydrate are less than a month-old, and while I'm worried that there might be a contaminant there from a dirty spatula, I was hoping to pick others' brains before I ordered new reagents.
Thank you!
make sure that malachite green is as oxalate salt. otherwise it will not work
If you are using glassware to make either of the solutions, beware of phosphate detergent residues. Wash all glassware thoroughly with MilliQ water before using it.
After mixing the ammonium molybdate and Malachite Green solutions, pass the mixture through a 0.2 micron filter using one of those disposable vacuum filtration funnel-bottle combination units to remove undissolved material. The solution should be light brown.
- Badges
- Science topic
- Similar topics
- Chemistry