POLARIC® Series

POLARIC®-NHS

[Fluorophores for labeling]

Others

POLARIC-NHS is a solvatochromic dye for protein labeling. It can label thiols via the amino group. For laser excitation, either 488 nm or 514 nm are appropriate.

Products

Code No. Product Name Size Merck CAT No. Merck ( Millipore / Sigma Aldrich )
Product Name
GC2021 POLARIC®-NHS 1 mg
  • Product Information

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    Properties of POLARIC-NHS

    Product name
    target reaction Absmax (nm)* FLmax (nm)*
    POLARIC-NHS solvent polarity reversible 480 592

    *Fluorescence wavelength changes upon the solvent polarity.

FAQ

  • Q In what situation does POLARIC change the color?
    A

    It is reported that the fluorescent wavelength of POLARIC is changed by the composition of lipid (Chem. Lett. 2011, 4, 989-991). On the other hand, POLARIC show no significant difference of fluorescence wavelength by pH changes.

  • Q Tell me the efficient labeling method using NHS reagent.
    A

    Prepare purified antibody (or other proteins). If you intended to crude protein sample, we recommend to purify protein using either affinity column, ultrafilteration or gel filteration before the labeling to increase labeling efficiency. In addition, avoid to use Tris-buffer, because Tris has primary amine and it strongly inhibit the reaction of NHS to the target protein.

    In some cases, reaction at 4oC for overnight gives higher degree of labeling compared with reaction at 37oC for 1 hour.

  • Q How can I get molar extinction coefficient of a protein at 280 nm?
    A

    Molar extinction coefficient of protein at 280 nm can be calculated by the methods of Gill and von Hippel (1989) Analytical Biochemistry, 182: 319-326  and Anthis and Clore (2013) Protein Science 22:851-858.

    You may find Web services to obtain them in the following sites. Goryo Chemical do not support the usage of these sites and use them according to the Terms and Conditions in each sites.

    http://protcalc.sourceforge.net/
    http://web.expasy.org/protparam/
    http://nickanthis.com/tools/a205.html

  • Q How can I prepare 0.1 M sodium bicarbonate buffer? Why this buffer is required?
    A

    Dissolve sodium bicarbonate (NaHCO3) to pure water and adjust the concentration to be 0.1 M. The pH should be in the range of 8.0 to 8.4. Alternatively, you can adjust pH by adding a small amount of Na2CO3  or  HCl.

    The reason to recommend this buffer is that the reaction of NHS ester and primary amines is more efficient at alkaline pH. Instead, you can use other alkaline buffers such as HEPES/phosphate/borate buffers.  Avoid to use Tris buffer because it has primary amines and inhibit the reaction of NHS with the target molecules.

  • Q My question is not in this FAQ list.....

Reference

M. Takao, Y. Nagai, M. Ito, T. Ohba (2018)
Genes Cells 23: 963-973 DOI:10.1111/gtc.12645

T. N. Mohammadi, A. T. Maung , J. Sato, T. Sonoda, Y. Masuda, K. Honjoh, T. Miyamoto. (2018)
J. Appl. Microbiol. in press DOI: 10.1111/jam.14134

M. Tanaka, T. Kikuchi, H. Uno, K. Okita, T. Kitanishi-Yumura, S. Yumura (2017)
Sci. Rep. 7: 12970 DOI:10.1038/s41598-017-13438-5

R. Omura, K. Nagao, N. Kobayashi, K. Ueda, H. Saito (2014)
J. Lipid Res. 55: 2423-2431 DOI:10.1194/jlr.D049445

N. Maishi, T. Kawamoto, N. Ohga, K. Yamada, K. Akiyama, K. Yamamoto, T. Osawa, Y. Hida, K. Hida (2013)
Oncol. Rep. 30: 1695-1700 DOI:10.3892/or.2013.2620

S. H. Son, Y. Yamagishi, M. Tani, M. Yuasa, K. Yamada (2011)
Chem. Lett. 40: 989-991 DOI:10.1246/cl.2011.989