We do clinical PCR and clean everything with 3% hydrogen peroxide or dilute sodium hydroxide to get rid of DNA and RNases. We also freeze thousands of samples. The markers work well for labeling reagents that come into contact with the cleaners, and the ink also withstands freezing. The moister that condenses on the tubes and containers does not bother the ink at all. I don't have to worry about labels coming off of ink smearing when handling reagents. I wish the tip were finer. The marker tends to bleed, so the writing is thicker than the tip. But the markers are still better than any other marker we have been using. Thank you.
Relative to other lab markers I have used, these markers rock! Most lab markers are pretty bad in my 20-year experience: they both dry out and come off. I've been using my black marker consistently for about three months. The marker still seems like it has plenty of ink in it. My VWR marker would have dried out by now. Further, our VWR lab markers do not write on paper very well because the tip is very dry. But these engineering markers can write on both paper and plastic.
I just purchased five packs for my lab! We primarily use the markers when culturing bacteria and maintaining C. elegans. They are shipped by Amazon, FYI. Shipping is fast. We are throwing out our Sharpies. Most of them stopped working only after a couple of weeks.
Discovered these markers on r/labrats after getting frustrated with labels wiping off in tissue culture from vwr cryo markers. These are the bomb.
Look, if you need to write on surfaces stored at cryo to physiological temperatures where if the writing came off, you'd be screwed or compromise cell line identification or sample identity, these are your markers. Yes, they are expensive. They are expensive because they are excellent at what they are designed to do. The cost of misidentifying precious samples significantly outweighs the cost of the pen.
- Works excellently at -196, -80, -20, 4, 25, 37 C. Can still see writing through frost which is nice when searching for vials quickly. Doesn't wipe off easily at the extreme low temperatures like typical cryomarkers or sharpie ultra fine, but may still get some slight shedding. Shedding usually only happens when I haven't wiped the marker in a while and a thicker layer of ink is dispensed while writing.
- Writing survives after being completely submerged in pure bleach or 200 proof ethanol over several days after testing.
- Has lasted several months of daily heavy use without fading like the typical Sharpie ultra fine point. Always writes with a bold black.
- It takes some getting used to waiting for them to dry, but unconsciously you get used to it. I am right handed so not as much of an issue. For those that are left handed, I'm sure you'll have to elevate the edge of you hand so you don't smear the writing as it dries. This is no different than when you're regularly labeling Eppendorf tubes.
- If you smear it on something e.g. deck of a tissue culture hood, you MUST spray it down with 70% ethanol very quickly and start scrubbing with ethanol to get it off before fully drying. Otherwise you'll just have to work it off with physical force over time.
- Tip can come out easily if you accidentally push too hard or wipe the tip fast. Being gentle helps here. Pen will start dispensing a lot of ink but if you just put the tip back in, wipe it, and store it as suggested, it goes back to normal.
- Sometimes dispenses too much ink if not wiped in a while. This can be frustrating when labeling vials quickly in a laminar flow good because the air flow will make the ink run while drying. You learn how to adapt your writing style to fix this. For Eppendorf tubes with the frosted writing area, because the ink is heavier (think more of an oil-based ink rather than alcohol based sharpie permanent marker) it likes to spread out more as it dries because of the surface is actually gritted.
- Doesn't always like to adhere to specific surfaces unless you've freshly re-primed the marker and write slower. I find that this happens on things that have special chemical resistance coatings e.g. Fisherbrand labeling tape (waterproof, oil & acid resistant).Buyer
- The red/pink marker writes in a pink color. Thought it was going to be red.- Think of this marker as writing in a bolder font when compared to an ultra fine point Sharpie permanent marker but finer than a Sharpie fine point. You may find that you cannot write as many things on say a 1.7 mL Eppendorf tube cap compared to an ultra fine point marker. You trade ultra fine writing for a writing point between ultra fine and fine sharpie permanent marker that is bold and ultra permanent.These markers were so good that my adviser adopted them for our tissue culture facility. I love them and think you will too.
There's no going back after having these.