Quantum dot calm

Nanocrystalline quantum dots (Qdots)

Register for free to listen to this article
Listen with Speechify
0:00
5:00
CARLSBAD, Calif.—Nanocrystalline quantum dots (Qdots) are seeing increased use in high-throughput binding experiments, but researchers from Invitrogen noted that most published work involved home-made systems, limiting their widespread utility. They therefore undertook a systematic examination of binding assays using commercially available Qdots and Alexa Fluor dyes, publishing their findings in Analytical Biochemistry.
 
Initially, the researchers conjugated small-molecule haptens (biotin, fluorescein and cortisol) to Qdots and monitored the binding of the fluorescent dyes conjugated to anti-hapten antibodies or natural binding partners using fluorescence resonance energy transfer (FRET) whereby low-wavelength light stimulated Qdot fluorescence that in turn stimulated dye fluorescence. They then used this system as the basis of a homogeneous competitive immunoassay of free haptens.
 
Using biotin-conjugated Qdots, the researchers found that streptavidin-conjugated Alexa Fluor had a 100-fold lower limit of detection for the biotin derivative biocytin than anti-biotin Alexa Fluor. Furthermore, they noted that fully biotinylated Qdots were 10-fold less sensitive than Qdots with 25 percent biotin coverage. They were likewise able to detect fluorescein and cortisol using antibody-conjugated dyes. As such, the researchers suggested that this study provides a first-step to widely applicable binding assays using Qdots.


Subscribe to Newsletter
Subscribe to our eNewsletters

Stay connected with all of the latest from Drug Discovery News.

March 2024 Issue Front Cover

Latest Issue  

• Volume 20 • Issue 2 • March 2024

March 2024

March 2024 Issue