Karter Scientific 250ml Glass Round Media Storage Bottles with GL45 Screw Cap, Borosilicate Glass, 251L6 (Case of 24)

Works as intended good for pressure cooking agar

absolutely horrible glass work. there is a large crease in the glass running from the bottom to the top, I ordered two and the crease is the exact same in both of them. I do chemistry and mycology work, so we will see how these do under pressure in my autoclave (pressure cooker) and how the glass (not the plastic lids) handles extremely acidic, corrosive chemicals and extremely quick, drastic changes in temperature. Will add photos & more details in ~3 weeks.UPDATE: Shattered inside of autoclave (pressure cooker), going through the process to request a refund/replacement now. wasn't thinking and threw away the broken glass without taking a picture, we will see what they can do.

Was super excited to use this bottle, I poured a small amount of warm water into the glass and I immediately hear a cracking noise. If this bottle could not support a temperature change as slight as this, I do not feel comfortable using it for anything else.

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.

Fantastic product for a great price. These pyrex media bottles are fantastic for pouring agar. For pressure cooking/sterilizing purposes I drilled a hole in the lid and covered it with a filter patch. These bottles have a perfect lip for pouring. No liquid pours back over the lip when pouring. Love these!!

The polypropylene cap leaves a lot to be desired when it comes to solvent safety. PTFE or teflon would’ve been preferable but that’s where price starts to rise. And I didn’t buy this for the cap. I bought it for cheap borosilicate glass.The glass these media bottles are made of is good. I diluted concentrated HCl, H2SO4, HNO3, and NaOH (separately) at my research lab in this bottle to see its heat resistance. The bottle was too hot to touch so in excess of 75 degrees Celsius. For HCl, I then tossed a giant stir bar in, cranked the stirplate rpm to 1000, heated the hot plate to 250 Celsius, and neutralized it with NaOH. It was HOT.And that glass still didn’t crack. 10/10

Good quality just not sure how accurate the measurement is. I have different 250ml devices and even used a 10ml device to count out 250ml and it wasn’t accurate. Using 250ml from a 10ml dropper came to about 230ml in this bottle.

The media could not be loaded.  The thickness of these chemical glass storage bottles is really thick compared to the thickness of my lab beakers.I ordered them for storage of my skincare chemicals formulas.I ordered the 100 ml chemical glass storage and I like it so I think I'm going to buy more but at 500 ml.

These aren't borosilicate. Cheaply made glass with an obvious seam, like something from the dollar store. Cap says they're good to autoclave, but they're not—bottom cracked on mine at 15 PSI. Don't bother.

If I could give zero stars I would.This isn't borosilicate glass. Ad says good to 140c and I poured a solution under 100c into it and the bottom cracked off. Complete POS

Pretty nice but you cant use magnetic stirer because of the round bottom!

if using magnetic stirrer huge indents that keep trapping the magnet.

Excellent quality bottle. VERY thick glass. The cap seals very nicely and easy to wash. I will be using this to store water in the fridge.