We had no problem with this product. It worked great we observed our protozoa before we used it and than observed after we used it and it slowed them down. We did have to use pipets but I was already expecting that. A little does go a long way the first time we did it we used to much and you couldn't see anything but globs of this stuff. I would buy this again.
This chemical worked as advertised, slowing the micro-organisms down to be able to study them. I mixed a drop of this with an equal amount of water to make it less viscous which let the organisms show some movement. The chemical bottle needs to be fitted with a dropper nozzle because pouring it to administer just one drop without a nozzle was a challenge, and impossible for younger hands. Delivery was within four days of ordering, and the 30 mL size was ideal for a hobbyist or school aged children.