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Cell Explorer™ Live Cell Labeling Kit *Red Fluorescence*

Image of HeLa cells stained with Cell Explorer™ Live Cell Labeling Kit *Red Fluorescence* (Cat#22609)in a Costar black wall/clear bottom 96-well plate. Cells were stained with Calcein Deep Red™ for 30 minutes and image was acquired with fluorescence microscope using Cy5 filter.
Image of HeLa cells stained with Cell Explorer™ Live Cell Labeling Kit *Red Fluorescence* (Cat#22609)in a Costar black wall/clear bottom 96-well plate. Cells were stained with Calcein Deep Red™ for 30 minutes and image was acquired with fluorescence microscope using Cy5 filter.
Flow Cytometry Analysis of Jurkat cells stained with Cell Explorer™ Live cells Labeling Kit (Cat#22609). Jurkat cells were washed once with HH buffer and stained with Calcein Deep Red™ for 30 minutes at 37C incubator. Cells were then washed with HH buffer and resuspended in HH buffer. The fluorescence intensities of Live cells (healthy, Red) and Dead cells (treated in 55°C water bath for 30 minutes, Green) were measured with NovoCyte 3000 flow cytometer using blue laser APC emission channel.
Ordering information
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Catalog Number22609
Unit Size
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Additional ordering information
InternationalSee distributors
ShippingStandard overnight for United States, inquire for international
Spectral properties
Excitation (nm)643
Emission (nm)663
Storage, safety and handling
H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22


Excitation (nm)
Emission (nm)
Our Cell Explorer™ fluorescence imaging kits are a set of tools for labeling cells for fluorescence microscopic investigations of cellular functions. The effective labeling of cells provides a powerful method for studying cellular events in a spatial and temporal context. This particular kit is designed to uniformly label live cells in red fluorescence. The kit uses a proprietary non-fluorescent dye that becomes strongly fluorescence upon entering into live cells. The dye is a hydrophobic compound that easily permeates intact live cells. The hydrolysis of the non-fluorescent substrate by intracellular esterases generates a strongly red fluorescent hydrophilic product that is well-retained in the cell cytoplasm. Cells grown in black-walled plates can be stained and quantified in less than two hours. The assay is more robust than the tetrazolium salt or Alarmar Blue™-based assays. It can be readily adapted for high-throughput assays in a wide variety of fluorescence platforms such as microplate assays, immunocytochemistry and flow cytometry. It is useful in a variety of studies, including cell adhesion, chemotaxis, multidrug resistance, cell viability, apoptosis and cytotoxicity. The kit provides all the essential components with an optimized cell-labeling protocol.


Fluorescence microscope

ExcitationCy5 filter set
EmissionCy5 filter set
Recommended plateBlack wall/clear bottom


Component A: Calcein Deep Red™2 vials
Component B: HHBS (Hanks' buffer with 20 mM Hepes)1 bottle (100 mL)

Example protocol


Protocol Summary
  1. Prepare cells in growth medium
  2. Remove the medium
  3. Add Calcein Deep Red™ working solution (100 µL/well for 96-well plates or 25 µL/well for 384-well plates)

  4. Incubate cells at 37°C for 30 minutes to 2 hours
  5. Wash the cells
  6. Examine the specimen under under fluorescence microscope with Cy5 filter (Ex/Em = 646/660 nm)
Important Note

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


For guidelines on cell sample preparation, please visit


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

Calcein Deep Red™ stock solution

Add 20 µL of DMSO into the vial of Calcein Deep Red™ (Component A) and mix well to make Calcein Deep Red™ stock solution. Note: 20 µL of Calcein Deep Red™ stock solution is enough for 1 plate. Note: Unused Calcein Deep Red™ stock solution can be aliquoted and stored at < -20 °C for 2 weeks if the tubes are sealed tightly. Avoid repeated freeze-thaw cycles and protect from light.


Add 20 µL of Calcein Deep Red™ stock solution into 10 mL of HHBS (Component B) and mix well to make Calcein Deep Red™ working solution. Protect from light.


  1. Remove the growth medium from the cell plates. Note: It is important to remove the growth medium in order to minimize the background fluorescence and increase the signal to background ratio.
  2. Add 100 µL/well (96-well plate) or 25 µL/well (384-well plate) Calcein Deep Red™ working solution into the cell plate.

  3. Incubate the cells in a 37°C, 5% CO2 incubator for 30 minutes to 2 hours.
  4. Remove the Calcein Deep Red™ working solution from the cells.

  5. Wash the cells with HHBS (Component B) for 2 to 3 times, and replace with HHBS.
  6. Image the cells using a fluorescence microscope with Cy5 filter (Ex/Em = 646/660 nm).


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Spectral properties

Excitation (nm)643
Emission (nm)663


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Journal: Autophagy (2016): 1440--1446
Differential detection of tumor cells using a combination of cell rolling, multivalent binding, and multiple antibodies
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Journal: Analytical chemistry (2014): 6088--6094
Size control and biological properties of monodispersed mesoporous bioactive glass sub-micron spheres
Authors: Hu, Qing and Li, Yuli and Miao, Guohou and Zhao, Naru and Chen, Xiaofeng
Journal: Rsc Advances (2014): 22678--22687
Versatile fabrication of nanoscale sol--gel bioactive glass particles for efficient bone tissue regeneration
Authors: Lei, Bo and Chen, Xiaofeng and Han, Xue and Zhou, Jiaan
Journal: Journal of Materials Chemistry (2012): 16906--16913


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A pharmaceutical company user's perspective on the potential of high content screening in drug discovery
Authors: Hoffman AF, Garippa RJ.
Journal: Methods Mol Biol (2007): 19
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Automated high content screening for phosphoinositide 3 kinase inhibition using an AKT 1 redistribution assay
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