AAT Bioquest

Helixyte™ 14 [Equivalent to SYBR 14] *5 mM*

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Physical properties
Molecular weightN/A
Spectral properties
Excitation (nm)489
Emission (nm)520
Storage, safety and handling
H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22
StorageFreeze (< -15 °C); Minimize light exposure


See also: Nucleus
Molecular weight
Excitation (nm)
Emission (nm)
Helixyte™ 14 has the same chemical structure of SYBR 14 (SYBR is the trademark of ThermoFisher). It is commonly used to monitor the viability of sperms. The proportion of living sperm in semen can be assessed by means of a dual staining technique using the stains SYBR-14 and propidium iodide (PI). Helixyte™ 14 is a nucleic acid stain, maximally absorbs at 488 nm and emits at 518 nm when bound to DNA. It stains the nuclei of living sperm bright green. Conversely, PI stains only nonmotile sperm that had lost their membrane integrity. The proportions of living and dead sperm can be determined by first staining with SYBR-14 and PI and then assessing stain uptake by flow cytometry. The proportions of living and dead sperm in mammalian semen can be readily identified through use of dual staining with SYBR-14 and PI and quantified through use of flow cytometry.


Flow cytometer

Excitation488 nm laser
Emission530/30 nm filter
Instrument specification(s)FITC channel

Fluorescence microscope

ExcitationFITC filter set
EmissionFITC filter set
Recommended plateBlack wall/clear bottom

Example protocol


Helixyte™ 14 working solution
Dilute the 5 mM Helixyte™ 14 stock solution to 10 to 20 µM Helixyte™ 14 working solution in the buffer of your choice.
Note     Prepare the working solution immediately before use.
Note     The Helixyte™ 14 working solution should not be stored or reused.
Note     The concentration of the Helixyte™ 14 working solution should be optimized for different cell types and conditions.


The following protocol is provided as a basic guide for the development of your own staining protocol. The concentrations of the reagents required for the optimal staining may vary depending on the density of cells (i.e. Sperm cells) and other materials in the sample.
  1. Dilute samples (e.g. Semen samples) in HEPES-buffered saline solution containing bovine serum albumin (10 mM HEPES, 150 mM NaCl, 10% BSA, pH 7.4).
  2. Add 5 µL of the diluted Helixyte™ 14 working solution to 1 mL of diluted samples.
  3. Incubate the samples at 37 °C for 5-10 minutes.
  4. Observe the samples using a fluorescence microscope with the FITC filter set. Alternatively, the samples can be analyzed by flow cytometry using the 530/30 nm filter. 


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Spectral properties

Excitation (nm)489
Emission (nm)520


View all 50 references: Citation Explorer
Cryopreservation of dog semen in a Tris extender with two different 1% soybean preparations compared with a Tris egg yolk extender.
Authors: Hermansson, Ulrika and Johannisson, Anders and Axnér, Eva
Journal: Veterinary medicine and science (2021)
Evaluation of the use of SYBR-14 and propidium iodide stain in a fluorescent computer-assisted spermatozoal quantification method in dogs.
Authors: Watts, John R
Journal: Reproduction in domestic animals = Zuchthygiene (2021): 89-102
Measurement of membrane integrity in canine spermatozoa using a fluorescent computer-assisted spermatozoal quantification method after SYBR-14/PI staining compared with manual counting after CFDA/PI staining.
Authors: Watts, John
Journal: Reproduction in domestic animals = Zuchthygiene (2021)
The impact of five years storage/biobanking at -80°C on mouse spermatozoa fertility, physiology, and function.
Authors: Raspa, Marcello and Putti, Sabrina and Paoletti, Renata and Barboni, Barbara and Ramal-Sanchez, Marina and Lanuti, Paola and Marchisio, Marco and D'Atri, Mario and Ortolani, Claudio and Papa, Stefano and Valbonetti, Luca and Bernabo, Nicola and Scavizzi, Ferdinando
Journal: Andrology (2021)
Butaphosphan and Cyanocobalamin Supplementation in Semen Extender on Chilled Boar Sperm Quality and Life Span.
Authors: Suwimonteerabutr, J and Chumsri, S and Tummaruk, P and Nuntapaitoon, Morakot
Journal: Frontiers in veterinary science (2020): 592162
Addition of butylated hydroxytoluene (BHT) in tris-based extender improves post-thaw quality and motion dynamics of dog spermatozoa.
Authors: Sun, Lingwei and Wu, Caifeng and Xu, Jiehuan and Zhang, Shushan and Dai, Jianjun and Zhang, Defu
Journal: Cryobiology (2020): 71-75
Effect of supplementation of valine to chicken extender on sperm cryoresistance and post-thaw fertilization capacity.
Authors: Bernal, B and Iglesias-Cabeza, N and Sánchez-Rivera, U and Toledano-Díaz, A and Castaño, C and Pérez-Cerezales, S and Gutiérrez-Adán, A and López-Sebastián, A and García-Casado, P and Gil, M G and Woelders, H and Blesbois, E and Santiago-Moreno, J
Journal: Poultry science (2020): 7133-7141
Soy lecithin as a potential alternative to powdered egg yolk for buck sperm cryopreservation does not protect them from mitochondrial damage.
Authors: Tabarez, Abigail and García, Wilber and Palomo, María Jesús
Journal: Animal reproduction science (2020): 106473
The synergistic effect of trehalose and low concentrations of cryoprotectants can improve post-thaw ram sperm parameters.
Authors: Öztürk, Ali Erdem and Bodu, Mustafa and Bucak, Mustafa Numan and Ağır, Vahit and Özcan, Ayşe and Keskin, Nazan and İli, Pınar and Topraggaleh, Tohid Rezaei and Sidal, Hümeyra and Başpınar, Nuri and Dursun, Şükrü
Journal: Cryobiology (2020): 157-163
Resveratrol protects boar sperm in vitro via its antioxidant capacity.
Authors: Sun, Linlin and Fan, Xiaoteng and Zeng, Yao and Wang, Liqian and Zhu, Zhendong and Li, Rongnan and Tian, Xiue and Wang, Yongjun and Lin, Yan and Wu, De and Zeng, Wenxian
Journal: Zygote (Cambridge, England) (2020): 1-8