How to Make Fluorescein from Highlighter Markers

video How to Make Fluorescein from Highlighter Markers
The above video demonstrates how to extract the chemical fluorescein from highlighter markers using no other chemical besides common rubbing alcohol. As is demonstrated in the video, fluorescein is spectacular to watch dissolve into water, especially under black light. Below is a list of other excellent videos that feature fluorescein.

Dr. Nozman's demonstrations (subtitled in English):


NurdRage (An excellent tutorial to make Fluorescein in the lab):

In addition to the above videos here are several links describing the process by which Fluorescein is used to detect trace amounts of blood:
amjy881 year ago
Can this be done with other highlighter colors or just yellow ones?
NightHawkInLight (author)  amjy881 year ago
Only yellow ones will have fluorescein, but other colors may also use somewhat interesting dyes.

What dyes exactly are contained in other highlighter colors?

How does the red/green fluorescein get used in yellow highlighters?
NightHawkInLight (author)  eerambach1 year ago
It changes colors depending on the concentration and the angle that it's looked at in certain lighting. If you have a test tube of the concentrated liquid one side will look yellow, the other red as you hold it up to a light. It's weird stuff.
MadisonH6 months ago

This is my science project I'm using!

pg13151 year ago
so since you said the Fluorescein is nontoxic, does that mean i can mix it in a drink to make it glow under a blacklight?
NightHawkInLight (author)  pg13151 year ago
It's non toxic, but from what I've read it does make you nauseous if you ingest it. There also might be some other chemicals in a highlighter that might not be as safe. To make drinks glow, mix them with club soda. It will glow blue under black light.

could I glow if I drank it?

How long will it last? Like if I put it in a bowl of water, will it begin to fade after a few days?
NightHawkInLight (author)  FoamboardRC1 year ago
It will last several weeks at minimum.
Is it possible just to squeeze the inner tube instead of messing with the bottle and alchohol?
gassie2021 year ago
Just a tip, if you want to obtain fluorescein powder, you can use the following steps:
1. obtain a flat glass surface, pour the flourescein on it in batches small enough that the surface tensoin keeps it together.
2. Use a hairdryer on highest heat at the lowest speed. watch out that you dont hold the hairdryer to close because je might blow the solution everywhere.
3. keep this up untill the fluorescein dries up and sticks to the glass.
4. use a flat metal, glass or plastic object like a razor or old credit card to scrape all the fluorescein off the glass and collect it in airtight pot.

A glass surface is not a must, but the powder is a lot easier to see. So you wont get fluorescein anywhere you don't want it.

Nice tutorial btw, had no idea markers contained that much of the stuff.
Make not "mark"
Would this florescence with an AC component around it? Meaning could you mark an electroluminescent wire or plate using capacitance?
Undwe1 year ago
highlighters have never been more interesting
dmb3211 year ago
awesome I will no longer see highlite markers the same way!
Chinasaur1 year ago
Would be cool if there were a reasonably diy reaction to conjugate this to amino acids for some diybio /in situ/ hybridizations (assuming you can also get oligonucleoties synthesized somewhere...)
Project 231 year ago
Dufva1 year ago
This is great fun, what percentage is the rubbing alcohol?

And how long did it take to evaporate the alcohol? :-)
NightHawkInLight (author)  Dufva1 year ago
I used 91% alcohol. The higher the concentration the better. It took about 20-30 minutes to evaporate without allowing it to boil very much. Too much of a boil causes little specks to get on everything around the pot.
Gabrock1 year ago
Awesome. What concentration has the alcohol you used?
billbillt1 year ago
I like how you showed us how to thk
action pig1 year ago
Very nicely done! This is now on my to-do list.
Camtron01 year ago