Karter Scientific50ml Glass Round Media Storage Bottles with GL32 Screw Cap, Borosilicate, (Case of 6)

I needed it to store a solution I was making, but they leak a little bit if shaken too hard, one of them was soda-lime glass instead of borosilicate, but I am happy with the purchase. Customer service was very friendly and helpful.

Very good quality lab equipment.

Everything you want for a bottle that could potentially hold harsh chemicals is here. The tops screw on tight and are sealed perfectly when closed, no leaks whatsoever and they are air tight. They can pour liquids very nicely without the liquid going everywhere even though there is no "spout" or anything like a beaker would have, not sure how but they pour as well as a beaker or better with no liquid running down the side or going where you don't want it. The borosilicate glass is thick and will withstand any chemical you throw at it (except hydrofluoric acid obviously, don't use that in glass) as well as withstanding temperatures normal glass will not. I could see a lot of uses for these outside of holding liquid chemicals that need a leak proof borosilicate bottle, maybe moonshiners might like them (probably the larger sized version of these same bottles, which I also bought and am also very happy with) or for the rest of us non moonshiners, maybe holding or mixing other beverages as you can shake these without fear of spilling. Any liquid you need to hold except hydrofluoric acid (sorry Walter White) these will do great and they come in whatever size you could want.

Perfect for my making agar needs!

These bottles are as advertised, but look at the pictures so you know what you're getting, specifically the cap. The inner ring does make for dripless pouring. But the hard plastic-on-plastic seal means it needs to be fully tightened every time. It is not like a rubber seal - if you stop tightening when you get resistance it *will* leak. The cap also retains a lot of liquid. If you have a sample in suspension and shake it before opening it's very hard not to drip some.

While I have not tried autoclaving or heat-shocking these bottles, they appear (at least superficially) to be the same quality as the ones we use in the lab. Good value for money. The threads on the bottles and the caps appear well-made, and they do not leak even when jostled extensively.Please note that these bottles (and products like them) are intended for storing liquid and not for measuring volumes. The markings are only there to give some vague (+/- 20%) idea of how much liquid you have left. If you want to measure volumes accurately you need to use a beaker or graduated cylinder that is labeled at least "Class B".I have never (and my lab at work truly buys the best of the best) encountered lab bottles with absolutely accurate volume measurements, so please don't hold that against this product.

Used these bottles for making agar for Petri dishes. This particular bottle was ran through a pressure cooker cycle for 20 minutes at 15psi (with the lid cracked to be vented) and the bottom burst out of it. Agar filled up and coated everything. This would’ve been detrimental to safety if I had lifted it out of the pressure cooker and it happened while I was holding it. Other bottle has held up, but I won’t be using it again after this experience as a safety concern. Karter Scientific offers no warranty on their product according to their website. Buyers beware.

I keep a couple aquariums and need to add a small amount of hydrochloric acid to each water change since the pH of our tap water is over 9. I buy the gallon jugs of straight acid for the pool, and used to use a tiny dropper to collect about 1.5ml to add to 5 gallons of water for a water change. It was precarious and dangerous collecting it from a gallon jug.Now with these I can pour a reasonable amount a small, safe container that's easy to keep inside. 100ml of HCl will keep me supplied for weekly water changes for over a year. The lid seals nicely and I can easily use a small dropper to collect only what I need without risk of spills. Definitely happy with this purchase.

excelente producto llego a tiempo

Estas botellas de medio son de excelente calidad y se ven muy bien. Las uso para almacenar soluciones en mi laboratorio.

Great if you're looking for borosilicate glass chips. Not so much if you want borosilicate bottles.

Just need to wash these before use. Good quality. Measure before you put your liquids in as the measurments aren't exact. Like this on all media bottles so nothing unexpected.

Llego antes, muy buen producto