New Study on Embryo Yield Prediction in Microspore Cultures

Coping with Increasing Demand for Wheat

Wheat (Triticum aestivum L.) is the second most important staple food crop worldwide, and it is accounting for a considerable amount of global human calorie consumption. Due to population growth and dietary changes, the demand for wheat is predicted to increase by up to 70% until 2050 [1]. Besides optimizing plant protection and plant nutrition, plant breeding exhibits a key role in increasing the productivity per land area.

Hence, new approaches and technologies are needed to meet this increasing demand.

Embryo Yield Prediction in Microspore Cultures with Impedance Flow Cytometry

In a recent study conducted by the applied research center Vegenov, the Amphasys Impedance Flow Cytometer Ampha Z32 was successfully used to characterize the developmental pathway of the microspores during the androgenesis process as well as to predict the embryo yield during the early stages of microspore cultures in wheat. The technology has proven to be a robust and reliable tool for embryo yield prediction within the first seven days of in vitro culture.

Impedance Flow Cytometry Allows the Early Prediction of Embryo Yields in Wheat (Triticum aestivum L.) Microspore Cultures

Abstract :

“Haplomethods are key biotechnological tools that make it possible to rapidly produce perfectly homozygous lines, speeding up plant breeding programs. Under specific stress conditions, microspores are reprogrammed toward sporophytic pathways, leading to embryo formation. Various endogenous and exogenous factors affect embryo yield in androgenesis, so the improvement of androgenesis efficiency requires the development of early, reliable and robust reactivity markers. During the last decade, numerous cytological, cellular and biochemical approaches were carried out to finely characterize microspore development and fate during androgenesis.

However, the different available markers are often species-dependent, and their development and application are time-consuming and cumbersome. In this study, we show the suitable use of impedance flow cytometry (IFC) to develop new robust, reliable and strong markers of androgenesis reactivity in wheat, leading to: (i) routine monitoring of the viability of heterogeneous cell cultures; (ii) quick and simple evaluation of stress treatment efficiency; and (iii) early prediction of embryo yields from microspore suspensions. IFC can therefore provide the fine characterization of all of the microspore developmental pathways that occur in a cell suspension, for embryogenic microspores as well as pollen-like microspores. IFC technology has become a very useful tool to track and characterize wheat microspores in androgenesis, but can also be adapted to other species and other in vitro cell culture systems.” [2]


[1] CGIAR Research Program on Wheat. 2017. Accessed Oct. 20. 2020

[2] J. Canonge, M.Philippot, C. Leblanc, P. Potin, M. Bodin. Impedance flow cytometry allows the early prediction of embryo yields in wheat (Triticum aestivum L.) microspore cultures. Plant Science 300 (2020) 110586.

Clostridium difficile bacteria

Quantifying Bacterial Spore Germination by Impedance Flow Cytometry

Ampha Z32 Used as a Diagnostic Tool for the Determination of Host Susceptibility to CDI (Clostridioides difficile infection)

CDI can occur as a result of antibiotic administration and consequent impairment of the gut microbiome, providing best growth conditions to C. diffiicile. This gram-positive bacterium produces toxins that can lead to severe intestinal diseases. Even though C. difficile can be treated with specific antibiotics, its spores are resistant to that treatment and can survive in the intestine. Therefore, CDI recurrence is quite frequent (20-30%!) and due mainly to germination of the dormant spores into vegetative bacteria.

The group of Prof. Nathan Swami at the University of Virginia has impressively shown how it is possible to determine the predisposition for CDI by measuring the germination of C. difficile spores to vegetative bacteria using Amphasys’ Impedance Flow Cytometer (Ampha Z32) on ex vivo cultured samples. This method is much faster (4-5 hours) and more sensitive than conventional, microbiological techniques, which normally need 24 hours for a reliable determination of the microbiome susceptibility to C. difficile spore germination. This underlines the potential of Impedance Flow Cytometry (IFC) as a point-of-care screening tool for CDI-vulnerable patients.

Please contact us, if you would like to read the full article!

Picture collage honoring Andrea Hunn for her project in Swiss Youth in Science

Analyzing the Effects of Natural Remedies on Cancer Cell Lines

Graduate Student Honored for Conducting Research on Cancer Cell Viability on the Ampha Z32

As part of her A-level project, Andrea Hunn used an Ampha Z32 Impedance Flow Cytometer to analyze the effects of selected natural remedies on cancer cell lines. 

Her project was selected to participate in the national “Swiss Youth in Science” competition. At Amphasys we are very proud and excited about Andreas accomplishment and are looking forward to follow her progress as a young scientist. 

Analyzing the Effects of Natural Remedies on Cancer Cell Lines with Impedance Flow Cytometry​

Her research deals with the question whether the addition of natural remedies such as Wogonin, Curcumin and  Epigallocatechingallat (EGCG) can be used to observe cell death. The aim was to measure cell death with the Amphasys Impedance Flow Cytometer, which was used for such a toxicity study on human cells for the first time.

Furthermore, the influence of natural remedy concentration and incubation time on cell death was investigated. The question arose whether the natural remedies only kill blood cancer cells or also other types of cancer, but not minor degenerated human cells.

Corn pollen on corn tassel

Improved Buffer for Corn Pollen Measurement

New AF8/AF9 Buffer for Pollen Analysis on the Ampha Z32 Pollen Analyzer

The Ampha Z32 Pollen Analyzer allows for a fast, reproducible and highly accurate determination of pollen viability along the pollen supply chain.

Our Amphasys R&D experts have developped two new and improved buffer for the analysis of large pollen such as corn, pumpkin, squash, zucchini and cotton. 

The new AmphaFluid buffer AF8 and AF9 improve sample preparation as they reduce sedimentation. Furthermore, a more accurate concentration measurement is enabled thanks to the new formula of the new buffers.

More information and recommendations for the measurement of pollen or microspores can be found in our “Pollen Analysis Instructions”. 


Support and External Maintenance in Times of COVID-19

We are all facing challenging times due to the current events around the global spread of COVID-19.

At Amphasys, we have taken all necessary measures to protect our team and are committed to providing our customers with full online support, products and services to enable their continued business operations during this extraordinary time.


To ensure optimal performance of the Ampha Z32, a yearly maintenance is indispensable. To respect the social distancing measures and to circumvent the current travelling restrictions we have implemented an “External Maintenance” solution. This maintenance model entails shipping of the instrument to our technical personnel, who will service it and send it back to our customers within a few days. For more information, please contact us at


Our support team is working remotely and is committed to helping you with any requests or questions you might have. Please contact us at


And last but not least, all our products can be ordered without any restrictions at

We hope that the global situation will soon improve.

Art illustration of nanoparticles

Nanotoxicity Screening by Impedance Flow Cytometry

Impedance Flow Cytometry: An Effective and Reliable Tool for Nanotoxicity Screening

Nanomaterials (NMs) have gained enormous attention due to their unique properties and have found use everywhere in daily life applications.

However, this widespread use resulted in an increased release of NMs and raised concerns on their adverse impact on the environment and on human health.

Until recently, there was a lack of standardized methods to assess the toxicity potential of these NMs as traditional toxicity assays have been shown to interfere with NMs resulting in false negatives or false positives.

In a recent study, published in the renowned scientific journal ‘Scientific Reports’, the reliability and applicability of label-free impedance flow cytometry for in-vitro nanotoxicity screening were investigated. The study concludes that IFC is a robust and reliable tool that is less prone to interferences due to the advantage of being label-free (1).

"Label-free impedance flow cytometry for nanotoxicity screening"


The development of reliable and cost-efficient methods to assess the toxicity of nanomaterials (NMs) is critical for the proper identification of their impact on human health and for ensuring a safe progress of nanotechnology. In this study, we investigated the reliability and applicability of label-free impedance flow cytometry (IFC) for in vitro nanotoxicity screening, which avoids time-consuming labelling steps and minimizes possible NM-induced interferences. U937 human lymphoma cells were exposed for 24 h to eight different nanomaterials at five concentrations (2, 10, 20, 50, and 100 μg/mL). The NMs’ effect on viability was measured using IFC and the results were compared to those obtained by trypan blue (TB) dye exclusion and conventional flow cytometry (FC). To discriminate viable from necrotic cells, the IFC measurement settings regarding signal trigger level and frequency, as well as the buffer composition, were optimised. A clear discrimination between viable and necrotic cells was obtained at 6 MHz in a sucrose-based measurement buffer. Nanomaterial-induced interferences were not detected for IFC. The IFC and TB assay results were in accordance for all NMs. The IFC was found to be robust, reliable and less prone to interferences due to the advantage of being label-free.

(1) Label-free impedance flow cytometry for nanotoxicity screening. Available from: [accessed Feb 27 2020].

Tomato in greenhouse

Impact of Pollen Quality on Tomato Seed Production

Large-Scale Research Project with Rijk Zwaan

In a recent customer research project, the Ampha Z32 Pollen Analyzer was used to evaluate the pollen quality of over 800 plants in 500 m2 greenhouse area.

The conclusions of the study show:

  • – A clear and distinctive correlation between pollen viability and seed set
  • – Pollen Viability needed to obtain optimum seed set varies per line
  • – The Ampha Z32 is more precise, faster and less prone to human bias than germination assays

If you are keen to know more about this project, please download the file for free.

Sorghum field

Breeding for Cold Stress Tolerance in Sorghum

Impedance Flow Cytometry Used to Analyze Sorghum Pollen Traits

A group of researchers from the Department of Plant Breeding at University of Giessen and the NPZ Innovation GmbH have conducted a study on reproductive cold stress tolerance in Sorghum F1 hybrids.

According to the study, the production of large pollen quantity with sufficient vitality also at lower temperature is considered to be the underlying physiological process to ensure seed set under cold stress in sorghum.

To quantify the amount as well as the viability of sorghum pollen, they have used the fast and non-invasive Ampha Z32 Pollen Analyzer

"Reproductive Cold Stress Tolerance in Sorghum F1 Hybrids is a Heterotic Trait"


The sensitivity of sorghum to pre-flowering cold stress, resulting in reduced pollen viability and poor seed set, is a major constraint for expanding growing areas into higher altitudes and latitudes. Nevertheless, compared to juvenile cold tolerance, reproductive cold tolerance in sorghum has received much less attention so far, and very little is known about its inheritance in F1-hybrids. We have composed a representative factorial (n=49 experimental F1-hybrids) for a comprehensive study on heterosis and combining ability for crucial tolerance traits as spikelet fertility (panicle harvestindex), seed yield and pollen viability, using field trials in stress- and control environments in Germany and Mexico as well as climate chamber experiments. Our results indicate a heterotic and rather dominant inheritance of reproductive cold tolerance in sorghum, with strong effects of female general combining ability (GCA) on F1-hybrid performance in our material. These findings, together with the comparatively low contribution of specific combining ability (SCA) effects and high heritability estimates, suggest that robust and efficient enhancement of reproductive cold tolerance is feasible viahybrid breeding.

(1) (PDF) Reproductive Cold Stress Tolerance in Sorghum F1 Hybrids is a Heterotic Trait. Available from: [accessed Feb 11 2020].

Comparison of germination assays and the Ampha Z32 for pollen viability analysis

Pollen Germination vs. Pollen Viability

Learn Why Germination Assays are Outdated

Pollen quality plays an important role in plant breeding and seed production. In-vitro germination is often regarded as the gold standard method for assessing pollen viability.

In a recent industry study on tomato pollen (Solanum lycopersicumin-vitro germination and Impedance Flow Cytometry on the Ampha Z32 Pollen Analyzer were compared.

The conclusion of this study are:

  1. Impedance Flow Cytometry (IFC) and germination show a good correlation when the correct pollen sample preparation and germination conditions are applied.
  2. IFC method is more accurate, less prone to bias and significantly faster. For the analysis of 100 samples a time savings of at least 10 hours is achieved.
  3. For optimal results, a controlled rehydration process of 30 min needs to be applied

If you are interested in the details of this comparison, please check out our Application Note.