Pollen Viability Analysis

The reliable determination of pollen quality is a key success factor in the seed and fruit production process. Experiments show a clear correlation between the viability (also called vitality) of pollen used for pollination and the obtained yield. External factors such as light, rain, temperature or chemical agents may influence pollen viability.

Amphasys provides an easy method to test and monitor pollen viability and thus a powerful tool to optimize the plant breeding, seed and fruit production processes. This is particularly important if laborious manual steps are involved and if pollen needs to be stored or transported from one site to another. Our mobile technology can be used in the lab, in the greenhouse or in-field. 1

Pollen Ploidy Analysis

Analyses performed on Ampha Z32 record impedance amplitude and phase signals of every single cell. These are displayed on dot plots and provide size and viability information, respectively. Pollen size of haploid and diploid tomato differ significantly which can be used in order to observe ploidy.

Figure: Analysis of ploidy and viability by impedance flow cytometry of tomato pollen. A, haploid; B, diploid tomato pollen.

Developmental Stages of Pollen

Multifrequency analyses in the radio frequency range interrogate electrical membrane and cytoplasmic characteristics that change during pollen maturation. It has been shown with brassica pollen, that the development from uni-nucleate to tri-cellular pollen can be followed by impedance flow cytometry. Therefore, Ampha Z32 allows to characterize the developmental stages of pollen. 

Figure: Developmental stages of Brassica pollen. A, Scheme of pollen development from uni-nucleate to tri-cellular pollen, n = vegetative nucleus, g = generative nucleus; B, Live images of microspores/pollen; C, DAPI staining of corresponding stages; D, IFC analysis on single bud level.

Milk Analysis

For the milk industry, the quality of raw milk is a major concern. High somatic cell counts mainly caused by bacterial infections and bacterial contamination caused by insufficient equipment sanitation or insufficient cleansing of the cow's udder and teats have an adverse impact on the milk products. Amphasys’ technology allows a direct determination of the somatic cell count in untreated raw milk. The bacteria count is obtained after centrifugation to remove milk fat and filtering with a 10 μm filter.

In-line Cell analytics for bioprocesses

Amphasys’ label-free approach provides a means for automated and continuous in-line single cell monitoring for bioprocesses and thereby offers a solution to circumvent the draw-backs of an off-line analysis. Until now, it was not possible to monitor directly and in real-time the quality of a cell culture in a bioreactor. For this purpose either indirect methods, i. e. the analysis of substrate or metabolite concentrations, or the determination of the viable biomass had to be applied. A direct measurement of the physiological conditions of single cells, however, was possible only off-line, because it requires the use of cell dyes.

Analysis of other single cells

Amphasys’ impedance flow cytometer enables its users to perform easy and statistically significant analyses of virtually any kind of single cells from humans, animals or plants (including pollen), as well as yeasts (including spores), bacteria, algae, and other micro-particles with a size ranging from about 1 to 150 μm. Examples of successful studies with bacteria, yeast, blood, cancer and stem cells are listed in the table below.

Cell source

Cell type

Application

Reference

Plant

Pollen

Viability & Germinability

Microspore & Pollen Quality

Heidmann et al. (2016)

Heidmann & Di Berardino (2017)

Bacteria

Bacillus

Viability & Membrane Potential Analysis

David et al. (2012)

Yeast

Saccharomyces

Viability

Cheung et al. (2010) 

Animal

Mouse hybridoma
Mouse 3T3 fibroblasts 
Erythrocytes
C2C12

Viability & Apoptosis
Cell differentiation
Parasite infection monitoring
Stem cells

Pierzchalski et al. (2012)
Schade-Kampmann et al. (2008)
Küttel et al. (2007)
Crocetti et al. (2014)

Human

PBMCs
MCF-7 / MCF-10
 

HL-60
U937

Cell differentiation 
Viability
Cancer Research

Cell differentiation
Cytotoxicity of nanoparticles

Schade-Kampmann et al. (2008) 
Pierzchalski et al. (2010) 
Crocetti et al. (2013)
Crocetti et al. (2014)
Cheung et al. (2010)
Caspersen et al. (2014)

Several Universities and other laboratories perform research on the basis of Amphasys’ technology. The method is especially interesting in cases where conventional, optical techniques fail, e.g. when dyes for fluorescence-based flow cytometers are not available or their use is disturbed by other factors, such as the presence of nano-particles.