Karter Scientific 50ml Glass Round Media Storage Bottles with GL32 Screw Cap, Borosilicate, (Case of 6)

These are perfect for me - I have been using these to travel (through TSA) without any issues. It is leak proof and is truly lab grade. It is easy to clean. This is dishwasher safe, as these are made to withstand temperatures of an autoclave.

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 size for mixing and storing my coffee brew water buffers and concentrates. Wide mouth that seals tightly with no leaks. Fits neatly in the back of the fridge. Clearly labelled measurement markings. Good value.

I've ordered 500mL media bottles from Karter before with no issue, all bottles were accurate to their description. The 250mL bottles, however, are not. At the bottom of the glass, you can see it has a 2 on it. If you didn't know, this classifies it as treated soda-lime glass. Real borosilicate glass, which is specifically used for its heat resistance, is type 1. You would see a 1 at the bottom of the bottle. I'd chalk this up to a mixup in the delivery process if it were not for all the other reviews posting about broken glasses after heating and even a few also pointing out that these are not true, heat resistant, borosilicate. Because of this, I'd say this is blatant false advertising on its face. And DANGEROUS false advertising at that. If you were to heat up one of these too quickly, they have potential to shatter, possibly causing cuts and even burns if there was any heated liquid inside the bottle. Instant 1 star, I'd give it a 0 if I could, just based on the safety hazard alone.

Used some of the 10 bottles I ordered (I ordered 5 sets with 2 bottles in each, at different times, I believe from the same seller) and they did well in autoclave for 4 cycles sterilization in a row (the autoclave was having issues and it stetilized the bottles in a series of repetitions, by the error) and the caps, nor the glass got damaged in a process in extended periods of high pressure and heat! This suggests that they are great quality. The design itself is good, but there is some accumulation of moisture even in the dry bottles, so I suggest to sterilize them on the tray without any moisture to prevent that. I will watch for any contamination issues, but they seem so far not leaking. I did sterilized ddH2O in some as well, and they probably will be used mostly for these and small volumes of media storage, such as molten agar for short term storage. I will update if any functionality is affected, but so far, for the price, these are great addition for small volume media storage, such as molten agar, small volumes of reagents that you might need to keep in several bottles to prevent contamination from reopening (such as liquid media for culturing) and some frequently used reagents/solutions/stetile water. I haven't used them for any dry powders, but if they are planning on doing so, I sugest to dry them well after 1st stetilization and use them then (if you don't need to keep the powders sterile, or resterilize the 2nd time of the dried bottles. I would make sure to keep the tape on both sides of the cap as they unscrew a little more than the other media bottles I used to prevent contamination. I haven't measured them exactly, but the opening on these is the standard as in the larger bottles as these caps fit on the other larger bottles. In a summary: great 100ml bottles for small (60ml mark is at half the bottle, so you can easily go for 50-60ml volumes in autoclave if using them for solutions/water/media) volumes that are inexpensive and good quality for its purpose.

These are amazing quality. I use them EVERY day in my lab and they hold up beautifully. The tops fit snugly, the glass is nice and thick, and it's easy to read the markings. The caps are nice and thick as well. My ONLY complaint is sometimes the seal isn't tight and the bottle will leak if I mix by shaking. BUT I got a magnetic mixer/stirrer and now I don't need to worry about it. I don't clean them because I only use them for deionized water and TBE buffer.

Very thick glass bottle and polymer closure. Perfect for safely storing mercury. Would have preferred to purchase just a single bottle.

These held up in the pressure canner. Nice glass jars suitable for making agar plates.

Does not have pouring rings which is very important, a little disappointed.

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

Excelente calidad pero bastante caro por pagar el envío en lugar de ir a una tienda física donde solo cuestan 30 pesos cada uno.

No los he probado con temperatura pero al lavar de despintaron

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.