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ReadiUse™ Preactivated APC Maleimide [Activated Allophycocyanin]

Flow cytometry analysis of whole blood cells stained with CD8 (SK1)-APC conjugate prepared with ReadiUse™ Preactivated APC Maleimide (Cat No. 2567). The fluorescence signal was monitored using an Aurora spectral flow cytometer in the R1-A channel
Flow cytometry analysis of whole blood cells stained with CD8 (SK1)-APC conjugate prepared with ReadiUse™ Preactivated APC Maleimide (Cat No. 2567). The fluorescence signal was monitored using an Aurora spectral flow cytometer in the R1-A channel
Flow cytometry analysis of whole blood cells stained with CD8 (SK1)-APC conjugate prepared with ReadiUse™ Preactivated APC Maleimide (Cat No. 2567). The fluorescence signal was monitored using an Aurora spectral flow cytometer in the R1-A channel
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Physical properties
Spectral properties
Correction Factor (280 nm)0.195
Extinction coefficient (cm -1 M -1)730000
Excitation (nm)651
Emission (nm)660
Storage, safety and handling
H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22
StorageRefrigerated (2-8 °C); Minimize light exposure
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See also: PE and APC
Correction Factor (280 nm)
Extinction coefficient (cm -1 M -1)
Excitation (nm)
Emission (nm)
ReadiUse™ Preactivated APC Maleimide is prepared by reacting highly purified allophycocyanin (APC) with SMCC. The NHS group of SMCC reacts with the lysine groups of APC, leaving maleimide groups available to react with free sulfhydryl groups on proteins to be conjugated. ReadiUse™ Preactivated APC Maleimide is highly purified to completely remove the unreacted SMCC, and lyophilized to powder. It is ready to use and will conjugate without further preparation upon mixing with sulfhydryl-containing target molecules such as reduced IgGs. The activated allophycocyanin can be easily conjugated to antibodies and other proteins without the use of added chemical crosslinking agents. These highly purified phycobiliproteins maintain their spectral characteristics of APC.

Example protocol


Reduction of Antibody
  1. Prepare a fresh solution of 1.0 M DTT (15.4 mg/100 µL) in distilled water. Antibody reduction can be carried out in different buffers, such as MES, phosphate, or TRIS (pH 6 to 8). For best results, antibody solutions should be >2 mg/mL. If less than 2 mg/mL, the antibody should be concentrated.
  2. Add 2 µL of 1.0 M DTT stock per 100 µL of antibody solution, and mix well. Let the antibody solution stand at room temperature for 30 minutes without additional mixing to minimize the reoxidation of cysteines.
  3. Purify the reduced antibody using a desalting column (Cat No. 60500) pre-equilibrated with 50 mM MES buffer (pH 6.0-6.5) and 2 mM EDTA.
  4. Measure the antibody concentration using a Nanodrop. (Con. (mg/mL) = A280nm/1.4).
    Note     Reduced antibodies are typically unstable. It is best to run the conjugation reaction immediately following purification.

Conjugate with ReadiUse™ Preactivated APC Maleimide
  1. Reconstitute ReadiUse™ Preactivated APC Maleimide in ddH2O to make a 10 mg/mL solution. For Cat No. 2567 (1 mg) reconstitute in 100 µL of ddH2O. If using Cat No. 2568 (5 mg), reconstitute in 500 µL of ddH2O. Reconstituted ReadiUse™ Preactivated APC Maleimide solutions are stable at 4 °C for up to one month, protected from light.
  2. Add the reduced antibody directly to the solution of ReadiUse™ Preactivated APC at a ratio of 130 µg APC/100 µg of reduced antibody.
  3. Rotate the mixture for 60 to 120 minutes at room temperature.
  4. Block any free sulfhydryl groups on the antibody. Prepare a fresh solution of 10 mg/mL N-Ethylmaleimide (NEM) in DMSO and add 3.4 µL per mg of antibody. Rotate for 20 minutes at room temperature. 

Conjugate Purification
  1. Purify the antibody/APC conjugate solution using size exclusion chromatography.
    Note     Typically the antibody/APC conjugate can be stored at 2-8 °C, protected from light, for up to 6 months. The best storage conditions for any particular conjugate must be determined by experimentation and depends on the stability of the antibody.


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Spectral properties

Correction Factor (280 nm)0.195
Extinction coefficient (cm -1 M -1)730000
Excitation (nm)651
Emission (nm)660

Product Family

NameExcitation (nm)Emission (nm)Extinction coefficient (cm -1 M -1)Correction Factor (280 nm)
ReadiUse™ Preactivated PE Maleimide [Activated R-Phycoerythrin]56557419600000.175
ReadiUse™ Preactivated PerCP Maleimide4776784060000.22



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Non-oxidative band-3 clustering agents cause the externalization of phosphatidylserine on erythrocyte surfaces by a calcium-independent mechanism.
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Journal: Biochimica et biophysica acta. Biomembranes (2020): 183231
Leukocyte-Derived Extracellular Vesicles in Blood with and without EpCAM Enrichment.
Authors: Nanou, Afroditi and Zeune, Leonie L and Terstappen, Leon W M M
Journal: Cells (2019)
Exogenous IL-9 Ameliorates Experimental Autoimmune Myasthenia Gravis Symptoms in Rats.
Authors: Yao, Xiuhua and Zhao, Jiarui and Kong, Qingfei and Xie, Xiaoli and Wang, Jinghua and Sun, Bo and Xu, Lixia and Mu, Lili and Li, Hulun
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A high-throughput neutralizing assay for antibodies and sera against hepatitis E virus.
Authors: Cai, Wei and Tang, Zi-Min and Wen, Gui-Ping and Wang, Si-Ling and Ji, Wen-Fang and Yang, Min and Ying, Dong and Zheng, Zi-Zheng and Xia, Ning-Shao
Journal: Scientific reports (2016): 25141
Monitoring genotoxicity in patients receiving chemotherapy for cancer: application of the PIG-A assay.
Authors: Horibata, Katsuyoshi and Ukai, Akiko and Ishikawa, Shigeo and Sugano, Ayako and Honma, Masamitsu
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Authors: Barnes, Theresa C and Spiller, David G and Anderson, Marina E and Edwards, Steven W and Moots, Robert J
Journal: Annals of the rheumatic diseases (2011): 366-72
A new procedure for the quantitative assessment of p-glycoprotein efflux pump associated with human T lymphocytes.
Authors: Vélez, Rosa and Sánchez, María del C and Lopez, Pablo and Yamamura, Yasuhiro
Journal: Ethnicity & disease (2008): S2-75-80
Dextramers: new generation of fluorescent MHC class I/peptide multimers for visualization of antigen-specific CD8+ T cells.
Authors: Batard, Pascal and Peterson, Daniel A and Devêvre, Estelle and Guillaume, Philippe and Cerottini, Jean-Charles and Rimoldi, Donata and Speiser, Daniel E and Winther, Lars and Romero, Pedro
Journal: Journal of immunological methods (2006): 136-48