AAT Bioquest


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Physical properties
Molecular weight688.79
Storage, safety and handling
H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22
StorageFreeze (< -15 °C)


Molecular weight
Psoralen-PEG3-Biotin is a photoactivatable reagent for biotinylating DNA or RNA. Psoralen-PEG3-Biotin has a psoralen group that can intercalate into double-stranded DNA or RNA and form covalent bonds with thymine and other pyrimidine bases when exposed to UV light (around 350 nm). Psoralen-PEG3-Biotin contains a polyethylene glycol (PEG) spacer arm that enhances the solubility and accessibility of the biotin moiety. Psoralen-PEG3-Biotin is used for selective labeling of cell surface proteins, biotinylation of hyaluronan, labeling of endotoxin for receptor binding studies, and crosslinking of nucleic acids for genomic investigations. It can also be used to study nucleic acid and protein interactions.

Example protocol


  1. Prepare a Psolaren-PEG3-Biotin stock solution by adding 70 μL (for Cat# 39050) or 350 μL (for Cat# 39051) of DMSO to the vial of Psolaren-PEG3-Biotin. 

    Note: Any unused stock solution should be divided into single-use aliquots and stored at -20 °C after preparation. Protect from light and avoid repeated freeze-thaw cycles.


The following protocol is to be used as a general guideline and may require optimization for your specific application and experimental system.

  1. Adjust DNA or RNA to the desired concentration (e.g., 20-100 μg/mL) in TE buffer (10 mM Tris, 1 mM EDTA, pH 7.4).

    Note: To improve the binding of dye to nucleic acid, DNA can be denatured by boiling for 5 minutes. After boiling, the DNA tube should be quickly cooled by placing it in a dry ice/ethanol bath.

  2. Add 1 μL of Psolaren-PEG3-Biotin stock solution to the DNA or RNA (100 μL volume) and mix well.

    Note: A serial dilution of the Psolaren-PEG3-Biotin stock solution may be required when using small reaction volumes.

  3. Irradiate the tube from above using a long wavelength UV light source for at least 20-30 minutes.

  4. To remove any non-reacted Psolaren-PEG3-Biotin, precipitate the sample with 0.5 M NaCl and two volumes of 100% ethanol at -20 °C for a minimum of 30 minutes. After centrifugation, wash the pellet with 70% ethanol and allow it to dry. Dissolve the biotinylated sample in water or a buffer of your choice.

  5. Biotinylated DNA can then be verified using HABA and gel electrophoresis.


Common stock solution preparation

Table 1. Volume of DMSO needed to reconstitute specific mass of Psoralen-PEG3-Biotin to given concentration. Note that volume is only for preparing stock solution. Refer to sample experimental protocol for appropriate experimental/physiological buffers.

0.1 mg0.5 mg1 mg5 mg10 mg
1 mM145.182 µL725.911 µL1.452 mL7.259 mL14.518 mL
5 mM29.036 µL145.182 µL290.364 µL1.452 mL2.904 mL
10 mM14.518 µL72.591 µL145.182 µL725.911 µL1.452 mL

Molarity calculator

Enter any two values (mass, volume, concentration) to calculate the third.

Mass (Calculate)Molecular weightVolume (Calculate)Concentration (Calculate)Moles



View all 50 references: Citation Explorer
Mutations in AcrR and RNA Polymerase Confer High-Level Resistance to Psoralen-UVA Irradiation.
Authors: Worley, Travis K and Weber, Emma A and Acott, Jedidiah D and Shimpi, Rahul S and Cole, Jessica M and Courcelle, Charmain T and Courcelle, Justin
Journal: Journal of bacteriology (2023): e0012623
Force-Dependent Intercalative Bulky DNA Adduct Formation Detected by Single-Molecule Stretching.
Authors: Liu, Yajun and Pei, Yufeng and Xu, Jingjing and Cheng, Yuanlei and Tong, Qingyi and You, Huijuan
Journal: Analytical chemistry (2022): 13623-13630
ERCC1-XPF targeting to psoralen-DNA crosslinks depends on XPA and FANCD2.
Authors: Sabatella, Mariangela and Pines, Alex and Slyskova, Jana and Vermeulen, Wim and Lans, Hannes
Journal: Cellular and molecular life sciences : CMLS (2020): 2005-2016
2D Gel Electrophoresis to Detect DNA Replication and Recombination Intermediates in Budding Yeast.
Authors: Zardoni, Luca and Nardini, Eleonora and Liberi, Giordano
Journal: Methods in molecular biology (Clifton, N.J.) (2020): 43-59
The Biochemical Role of the Human NEIL1 and NEIL3 DNA Glycosylases on Model DNA Replication Forks.
Authors: Albelazi, Mustafa S and Martin, Peter R and Mohammed, Soran and Mutti, Luciano and Parsons, Jason L and Elder, Rhoderick H
Journal: Genes (2019)
Cho Endonuclease Functions during DNA Interstrand Cross-Link Repair in Escherichia coli.
Authors: Perera, Anthonige Vidya and Mendenhall, James Brian and Courcelle, Charmain Tan and Courcelle, Justin
Journal: Journal of bacteriology (2016): 3099-3108
DNA Intercalated Psoralen Undergoes Efficient Photoinduced Electron Transfer.
Authors: Fröbel, Sascha and Reiffers, Anna and Torres Ziegenbein, Christian and Gilch, Peter
Journal: The journal of physical chemistry letters (2015): 1260-4
Induction of direct repeat recombination by psoralen-DNA adducts in Saccharomyces cerevisiae: defects in DNA repair increase gene copy number variation.
Authors: Saffran, Wilma A and Ahmed, Anam and Binyaminov, Olga and Gonzalez, Cynthia and Gupta, Amita and Fajardo, Manuel A and Kishun, Devindra and Nandram, Ashana and Reyes, Kenneth and Scalercio, Karina and Senior, Charles W
Journal: DNA repair (2014): 87-96
Bypass of a psoralen DNA interstrand cross-link by DNA polymerases β, ι, and κ in vitro.
Authors: Smith, Leigh A and Makarova, Alena V and Samson, Laura and Thiesen, Katherine E and Dhar, Alok and Bessho, Tadayoshi
Journal: Biochemistry (2012): 8931-8
A method for genome-wide analysis of DNA helical tension by means of psoralen-DNA photobinding.
Authors: Bermúdez, Ignacio and García-Martínez, José and Pérez-Ortín, José E and Roca, Joaquim
Journal: Nucleic acids research (2010): e182