AAT Bioquest

Portelite™ Fluorimetric Sodium Ion Quantification Kit


Molecular weight
Excitation (nm)
Emission (nm)
Portelite™ Fluorimetric Sodium Ion Quantification Kit™ uses our robust sodium ion indicator dye, SoNa™ 520, which exhibit great fluorescence intensity enhancement upon binding to sodium ions. SoNa™ 520 is perhaps the most robust sodium ion indicator with high selectivity. It enables the kit to be useful for the rapid determination of sodium concentrations in a variety of samples compared to the other commercial sodium ion assays. This nanodrop-based assay kit requires a small amount of sample, it is particularly suitable for the determination of sodium ion concentration in fields or on site. Quantifying sodium ions is important in various scientific fields and industries, including biochemistry, medicine, environmental analysis, and food science etc. There are several methods commonly used to quantify sodium ions, including flame photometry, ion-selective electrodes (ISE), atomic absorption spectroscopy and fluorescence spectrophotometry. Flame photometry and atomic absorption spectroscopy require the inflammation of the samples. They are tedious to use and require expensive and sophisticated instrumentation. Ion-selective electrodes require large volumes of samples and often have low selectivity. Among all the methods, fluorescence spectrophotometry is the most convenient method for quantifying sodium ions. Fluorescence spectrophotometry involves complexing sodium ions with specific reagents and measuring the resulting fluorescence changes. SoNa™ 520 is perhaps the best sodium ion indicator for rapidly determining sodium ion concentration in combination with a fluorescence device such as a fluorescence Nanodrop spectrophotometer or a fluorescence microplate reader.


Qubit Fluorometer

Excitation480 nm
Emission530 nm
Instrument specification(s)0.2 mL PCR tube

CytoCite Fluorometer

Excitation480 nm
Emission530 nm
Instrument specification(s)0.2 mL PCR tube


Example protocol


Important Note

Thaw all the kit components at room temperature before starting the experiment.

Protocol Summary
  1. Prepare the test samples and serially diluted sodium standards.

  2. Add 100 µL of the SoNa™ 520 working solution to your test samples.

  3. Incubate at room temperature for 5-10 minutes.

  4. Monitor the fluorescence intensity with a CytoCite™ fluorometer or Qubit™ fluorometer.


Unless otherwise noted, all unused stock solutions should be divided into single-use aliquots and stored at -20 °C after preparation. Avoid repeated freeze-thaw cycles

SoNa™ 520 Stock Solution
  1. To prepare a SoNa™ 520 stock solution, add 100 μL of DMSO to the vial containing SoNa™ 520 (Component A).

    Note: Prepare a single aliquot of unused SoNa™ 520 stock solution and store it at ≤ -20 ºC, protected from light. Avoid freeze/thaw cycles.


For convenience, use the Serial Dilution Planner:

Sodium Standard
Add 300 µL of distilled water to the Sodium Standard vial (Component C) to prepare a 250 mM standard stock solution. Next, dilute this 250 mM stock solution with Assay Buffer to achieve a 40 mM solution (SS1). Then, perform 1:2 serial dilutions of the 40 mM solution to obtain a series of sodium standards (SS2 to SS7).


SoNa™ 520 Working Solution
  1. Prepare the SoNa™ 520 working solution by adding 100 μL of SoNa™ 520 (Component A) to 5 mL of Assay Buffer (Component B), and protect the working solution from light by covering it with foil or placing it in a dark location.

    Note: For optimal results, use this solution within a few hours after preparing it.

    Note: 5 mL of working solution is enough for 100 tests.


Important Note

The acceptable sample volume can range from 1 to 20 μL, depending on the estimated concentration of the nucleic acid sample. The following protocol is based on a sample volume of 10 μL.

  1. Add 100 µL of SoNa™ 520 working solution to each Cytocite™ sample tube (Cat No. CCT100) or to an equivalent 0.2 mL PCR tube.

  2. Add 100 μL of Sodium Standards or test samples to each tube. Mix each tube by vortexing for 2-3 seconds.

  3. Incubate all the tubes at room temperature for 5-10 minutes.

  4. Insert the samples into either the CytoCite™ or Qubit™ devices. Use the green fluorescence channel to measure the fluorescence intensity. Be sure to follow the specific procedures for the CytoCite™ Fluorometer. For detailed instructions, refer to the link below:


Preparation of Standard Calibration Curve

For Portelite™ assays, you can create a calibration curve using the Sodium Standards. Below is a simple protocol for generating a customized Sodium standard curve.

  1. Perform a 1:2 serial dilution. First, add Sodium Standard #2 (Component D) into the Assay Buffer (Component B). Then, create the following Sodium standard dilutions: 40 mM, 20 mM, 10 mM, 5 mM, 2.5 mM, 1.25 mM, and 0.625 mM.

    Note: Final, in well concentration of the sample, will be 20, 10, 5, 2.5, 1.25, 0.625, 0.3125 mM.

  2. Add 100 µL of the SoNa™ 520 working solution to each tube.

  3. Add 100 µL of either standards or samples into a 0.2 mL PCR tube.

  4. Incubate the reaction at room temperature for 5-10 minutes.

  5. Insert the samples into the CytoCite™ device and use the green fluorescence channel to monitor the fluorescence intensity.


Common stock solution preparation

Table 1. Volume of DMSO needed to reconstitute specific mass of Portelite™ Fluorimetric Sodium Ion Quantification Kit 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 mM138.75 µL693.751 µL1.388 mL6.938 mL13.875 mL
5 mM27.75 µL138.75 µL277.5 µL1.388 mL2.775 mL
10 mM13.875 µL69.375 µL138.75 µL693.751 µL1.388 mL

Molarity calculator

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

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


Open in Advanced Spectrum Viewer

Spectral properties

Excitation (nm)491
Emission (nm)511



View all 50 references: Citation Explorer
Importance of palm's heart for pregnant women.
Authors: Kushi, Efrem Negash and Belachew, Tefera and Tamiru, Dessalegn
Journal: Journal of nutritional science (2023): e5
Design of a Nutritional Survey to Detect High Dietary Salt Intakes and Its Usefulness in Primary Care Compared to 24-Hour Urine Sodium Determination.
Authors: Jiménez Rodríguez, Amelia and Palomo Cobos, Luis and Rodríguez-Martín, Amelia and Fernández Del Valle, Patricia and Novalbos-Ruíz, José P
Journal: Nutrients (2023)
Resolving Pseudohyponatremia: Validation of Plasma Sodium on Radiometer ABL800 Blood Gas Analyzers for Immediate Reflex Testing.
Authors: Vera, Michael A and Sutphin, Angela and Hansen, Lisa and El-Khoury, Joe M
Journal: Laboratory medicine (2022): e105-e108
Asparaginase-induced pseudohyponatremia, a case-driven working strategy in pediatric patients.
Authors: Evenepoel, A and Herroelen, P and Lanckmans, K and van der Werff Ten Bosch, J and Martin, M and Weets, I and van Dalem, A
Journal: Acta clinica Belgica (2022): 832-836
Hyponatremia-Long-Term Prognostic Factor for Nonfatal Pulmonary Embolism.
Authors: Ouatu, Anca and Mihai, Madalina Stefana and Tanase, Daniela Maria and Dascalu, Cristina Gena and Dima, Nicoleta and Serban, Lacramioara Ionela and Rezus, Ciprian and Floria, Mariana
Journal: Diagnostics (Basel, Switzerland) (2021)
Surface molecularly imprinted polymer based on core-shell Fe3O4@MIL-101(Cr) for selective extraction of phenytoin sodium in plasma.
Authors: Jia, Mengtian and Zhu, Yanyan and Guo, Dong and Bi, Xiaogang and Hou, Xiaohong
Journal: Analytica chimica acta (2020): 211-220
Infrared enthalpymetric methods: A new, fast and simple alternative for sodium determination in food sauces.
Authors: Tischer, Bruna and Teixeira, Iberê Damê and Filoda, Paula Freitas and Alessio, Keiti Oliveira and Barin, Juliano Smanioto and Duarte, Fábio Andrei and Kipper, Liane Mahlmann and Helfer, Gilson Augusto and Costa, Adilson Ben da
Journal: Food chemistry (2020): 125456
Case report: An index of suspicion in hyponatraemia.
Authors: Barkhuizen, Marizna and Hoffmann, Mariza and Zöllner, Ekkehard Wa and Erasmus, Rajiv T and Zemlin, Annalise E
Journal: Biochemia medica (2019): 011002
Heritability and individuality of the plasma sodium concentration: a twin study in the United States veteran population.
Authors: Timmons, Andrew K and Korpak, Anna M and Tan, Jenny and Moore, Kathryn P and Liu, Cindy H and Forsberg, Christopher W and Goldberg, Jack and Smith, Nicholas L and Cohen, David M
Journal: American journal of physiology. Renal physiology (2019): F1114-F1123
Development of a rapid and accurate method for the determination of sodium in vacuum gas oils (VGOs) by ICP-OES.
Authors: Gazulla, María Fernanda and Andreu, Cristina and Rodrigo, Marta and Orduña, Mónica and Ventura, María Jesús
Journal: Talanta (2018): 600-605