Extracting Fluorescein for Glow-in-the-Dark Fun


Extract fluorescein from highlighters to use in a variety of beautiful ways.


Affiliate links to chemicals.

*Note: These chemicals can be purchased locally at stores such as Walmart/Target.


  • Test tube holder

  • Pliers

  • Large test tube

  • Stirring rod 

  • Eye dropper

  • Dropping bottle (filled with rubbing alcohol)

  • Alcohol burner + stand + lighter

  • UV light (optional but really makes the fluorescein bright)


1. Pull off backs of highlighters with pliers. Remove the yellow tubes.

2. Pinch yellow tube with test tube holders and hold in test tube.

3. With dropper bottle, squeeze alcohol into the yellow tube.  The fluorescein and alcohol will collect at the bottom of the test tube.  The yellow tube will become white as the fluorescein is removed; pour into glass beaker.

4. Repeat step 3 with the rest of the highlighters.  This will take awhile!

5. Place the beaker on the stand and light the alcohol lamp.

6. Boil for about 20 minutes or until the liquid reduces to ~100 mL.

7. Use eye dropper to extract fluorescein.

The Science Behind the Reaction

Fluorescein is repelled by the alcohol so as the alcohol enters, the fluorescein leaks out.  We then burned off the alcohol and were left with just the Fluorescein.

This chemical looks cool but it also has a lot of important uses, like tracing blood samples, leaving a trail in the body when digested, and helping to locate missing planes.  Wow!

Keep Experimenting!

Try some at-home Crime Scene Investigation.




-3% hydrogen peroxide


-Dark room

-UV light source

-Piece of paper

-Steak (or some slab of meat)

-Another red substance (like strawberry jelly)


1. Purchase a steak from the store and rub a streak of blood on a piece of paper.

2. Rub a smear of another red substance on the other side of the paper, like strawberry jelly.

3. Spray Fluorescein on the two smears followed by a spray of 3% hydrogen peroxide.

4. Go into a dark room and turn on the UV light.