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Mixed Bases
Interesting Science Facts

Fluorescein—painting rivers green!

Chicago River

The Chicago River on St. Patrick’s Day 2009. While the tradition continues, fluorescein is no longer used to provide the green color; the current recipe is a tightly guarded secret (photograph courtesy of Mike Boehmer).

One of the most ubiquitous modifications attached to oligos is the bright green fluorophore known as Fluorescein, FITC, or FAM (Fluorescein amidite). Attaching the fluorophore to oligonucleotides is not its only use though.

In 1961 Steve Bailey was the business manager of the Chicago Journeymen Plumbers Union, Local 110. One afternoon a plumber stopped into the office wearing white coveralls that were nearly covered with green stains. When Bailey asked about the cause of the green stains, the plumber explained that he had been checking for potential sources of pollution to the Chicago River. This was done by dumping the bright green dye fluorescein into waste pipes around the river and checking to see if any of the green dye showed up in the river.

The bright green on the plumber’s coveralls gave Bailey an idea with a different slant. Instead of using fluorescein as a pollution control, why not dump a hundred pounds of the stuff into the river, and turn the river green for St. Patrick’s Day? In an impressive display of the clout of a strong union in a strong union town, that is just what they did.

So next St. Patrick’s day pull out a FAM-labeled oligo from the back of your lab fridge, and raise a glass to the astoundingly useful dye, and then raise it one more time for that mighty bright green river, The Chicago.

IDT provides a selection of fluorescein dyes, including Fluorescein Freedom™ Dyes that have no patent licensing restrictions. 

Additional reading

Fluorescent dyes with no licensing restrictions—a growing portfolioFluorescent dyes suitable for commercial and diagnostic applications and that have no patent licensing restrictions. A table of Freedom Dye alternatives for commonly used proprietary dyes is provided. 

Click chemistry-generated internal dye-labeled oligonucleotidesIn general terms, “Click Chemistry” describes reactions used to join small chemical subunits in a modular fashion, yielding singular reaction products that are typically physiologically stable and stereospecific.

Need a non-standard modification?IDT offers 89 modifications that are not listed in our online catalog. A few of the more popular ones are described along with information on how to order them. IDT will consider any modification you have in mind. Please make such inquiries to noncat@idtdna.com

Author: Brendan Owens is the manager of the technical support group at IDT.

© 2011, 2017 Integrated DNA Technologies. All rights reserved. Trademarks contained herein are the property of Integrated DNA Technologies, Inc. or their respective owners. For specific trademark and licensing information, see www.idtdna.com/trademarks


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