Methods for Spatio-Temporal Analysis of Embryo Cleavage In Vitro

Automated or semiautomated time-lapse analysis of early stage embryo images during the cleavage stage can give insight into the timing of mitosis, regularity of both division timing and pattern, as well as cell lineage. Simultaneous monitoring of molecular processes enables the study of connections between genetic expression and cell physiology and development. The study of live embryos poses not only new requirements on the hardware and embryo-holding equipment but also indirectly on analytical software and data analysis as four-dimensional video sequencing of embryos easily creates high quantities of data. The ability to continuously film and automatically analyze growing embryos gives new insights into temporal embryo development by studying morphokinetics as well as morphology. Until recently, this was not possible unless by a tedious manual process. In recent years, several methods have been developed that enable this dynamic monitoring of live embryos. Here we describe three methods with variations in hardware and software analysis and give examples of the outcomes. Together, these methods open a window to new information in developmental embryology, as embryo division pattern and lineage are studied in vivo

Quantitative Phase Imaging for Label-Free Analysis of Cancer Cells—Focus on Digital Holographic Microscopy

To understand complex biological processes, scientists must gain insight into the function of individual living cells. In contrast to the imaging of fixed cells, where a single snapshot of the cell’s life is retrieved, live-cell imaging allows investigation of the dynamic processes underlying the function and morphology of cells. Label-free imaging of living cells is advantageous since it is used without fluorescent probes and maintains an appropriate environment for cellular behavior, otherwise leading to phototoxicity and photo bleaching. Quantitative phase imaging (QPI) is an ideal method for studying live cell dynamics by providing data from noninvasive monitoring over arbitrary time scales. The effect of drugs on migration, proliferation, and apoptosis of cancer cells are emerging fields suitable for QPI analysis. In this review, we provide a current insight into QPI applied to cancer research

Det digitala holografiska mikroskopet : innovativ teknik för analys av levande celler

Bakgrund: Digital holografi är en ny teknik som de senaste fem åren använts för att studera levande celler. Tekniken utgör en innovativ, icke-förstörande metod som möjliggör studier av levande celler över tid. Material och metoder: Litteraturen har valts ut genom att söka på redan kända forskargrupper och företag som arbetar både med digital holografi och cellstudier samt PubMed-sökningar. Resultat och sammanfattning: Digital holografi ger kunskap om cellernas brytningsindex, som kan ändras under olika förhållanden. De parametrar som kan mätas ger unik information om cellantal, cellernas area, tjocklek och volym, vilket kan omvandlas till proliferation, viabilitet och celldöd. Tekniken är relativt billig, snabb och enkel att använda.Background: Digital holography is a novel technique that has been used for about five years to study living cells. The technique is an innovative, non-destructive method with possibilities to study living cells over time. Materials and methods: The literature in this paper was selected on the basis of already known research groups and companies in the field working with both digital holography and cell studies, as well as PubMed search. Results and conclusions: Digital holography is a method that gives us information about the refractive index of cells, which can change under different circumstances. The unique measurable parameters are the cell number, cell area, thickness and volume, which can be transformed to proliferation, viability and cell death. The technique is cheap, fast and simple to use

Hessische Naturwaldreservate im Portrait: Die Waldvegetation

Seit 2007 stellt die Reihe „Hessische Naturwaldreservate im Portrait“ Ergebnisse des hessischen Naturwaldreservate-Programms vor. Mit der vollständigen Erfassung der Waldvegetation an den fast 1500 Rasterpunkten der hessischen Naturwaldreservate in den Jahren 2007 bis 2021 wurden wichtige Grundlagen für das Verständnis der ökologischen Bedingungen und Prozesse in Wäldern mit natürlicher Entwicklung wie auch in bewirtschafteten Vergleichsflächen gelegt. Für alle Aufnahmeflächen liegt nun die Information über die dort ausgebildeten Vegetationstypen und deren Artenvielfalt vor. Insgesamt elf Waldtypen konnten in den hessischen Naturwaldreservaten gefunden werden. Einige davon sind weit verbreitet und in mehreren Gebieten anzutreffen, andere sind auf einzelne Naturwaldreservate oder Teile von ihnen beschränkt. Mithilfe der erhobenen Vegetationsdaten konnten floristische und strukturelle Unterschiede zwischen den Waldgesellschaften, aber auch zwischen den Ausprägungen einer Waldgesellschaft in Totalreservat und Vergleichsfläche auf einer einzigartig breiten Datenbasis herausgearbeitet werden. Für die Vegetation unbewirtschafteter und bewirtschafteter Hainsimsen-, Waldmeister- und Waldgersten-Buchenwälder können damit sehr weitreichende Aussagen getroffen werden. Nach dem ersten vollständigen Aufnahmedurchgang in den hessischen Naturwaldreservaten kommt die Vegetationserfassung nicht zum Abschluss. Vielmehr wurde damit eine Basis für Zeitreihen geschaffen, die Aussagen über die mittel- und langfristige Entwicklung der Waldvegetation in Naturwaldreservaten ermöglichen. Für die Zukunft sind daher Wiederholungsuntersuchungen im Rahmen eines Langzeit-Monitorings von großer Bedeutung, wie sie für das Naturwaldreservat Hohestein bereits vorliegen

Non-invasive, label.free cell counting and quantitative analysis of adherent cells using digital holography

Manual cell counting is time consuming and requires a high degree of skill on behalf of the person performing the count. Here we use a technique that combines digital holography and phase contrast microscopy allowing label-free and completely non-invasive cell counting directly in cell culture vessels with adherent viable cells. Digital holography can provide both quantitative and qualitative phase information from a single hologram. The recently constructed microscope HolomonitorTM M2 combines digital holography with the benefits of the commonly used phase contrast microscope, allowing us to combine the advantages of light imaging with the possibility of achieving quantitative information on cellular shape, area, confluence and optical thickness. This project aimed at determining the accuracy and repeatability of cell counting measurements using digital holography compared to the conventional manual cell counting method using a haemocytometer. The collected data were also used to determine cell size and cellular optical thickness. The results show that digital holography can be used for non-invasive cell counting as precisely and much faster than conventional manual cell counting

Digital holographic microscopy : innovative and non-destructive analysis of living cells

Digital holography is a novel technique that has been developed recently to study living cells. The technique is an innovative, non-destructive method with possibilities to study living cells over time. We are investigating cell number, growth, viability and death of adherent cells using digital holography, which is a novel, label-free, imaging technique for biological applications. We have recently demonstrated that digital holography is highly comparable to the conventional manual cell counting method using a hemocytometer (Mölder et al., 2008). Digital holography is a method that gives us information about the refractive index of cells, which can change under different circumstances. The technique is cheap, fast and simple to use. The unique measurable parameters are the cell number, cell area, thickness and volume, which can be transformed to proliferation, migration, viability and cell death. The digital holographic images produced can provide both quantitative and qualitative phase information from a single hologram. Future applications can include real-time cell monitoring of various parameters of cells of different diseases in response to clinically relevant compounds

Induction of morphological changes in death-induced cancer cells monitored by holographic microscopy.

We are using the label-free technique of holographic microscopy to analyze cellular parameters including cell number, confluence, cellular volume and area directly in the cell culture environment. We show that death-induced cells can be distinguished from untreated counterparts by the use of holographic microscopy, and we demonstrate its capability for cell death assessment. Morphological analysis of two representative cell lines (L929 and DU145) was performed in the culture flasks without any prior cell detachment. The two cell lines were treated with the anti-tumour agent etoposide for 1-3days. Measurements by holographic microscopy showed significant differences in average cell number, confluence, volume and area when comparing etoposide-treated with untreated cells. The cell volume of the treated cell lines was initially increased at early time-points. By time, cells decreased in volume, especially when treated with high doses of etoposide. In conclusion, we have shown that holographic microscopy allows label-free and completely non-invasive morphological measurements of cell growth, viability and death. Future applications could include real-time monitoring of these holographic microscopy parameters in cells in response to clinically relevant compounds

ICOS Sweden station presentation poster

ICOS - Integrated Carbon Observation System - is a European research infrastructure to quantify and understand the greenhouse gas balance of the European continent and of adjacent regions. ICOS Sweden is the Swedish contribution to this European effort and is a cooperation of several research institutes.The ICOS Sweden measurement sites have been chosen with the main aim to cover typical Swedish conditions, but at the same time considering a broader Nordic context and the European perspective. More information on www.icos-sweden.s

Modelling of growing season methane fluxes in a high-Arctic wet tundra ecosystem 1997-2010 using in situ and high-resolution satellite data

Methane (CH4) fluxes 1997-2010 were studied by combining remotely sensed normalised difference water index (NDWI) with in situ CH4 fluxes from Rylekaerene, a high-Arctic wet tundra ecosystem in the Zackenberg valley, north-eastern Greenland. In situ CH4 fluxes were measured using the closed-chamber technique. Regression models between in situ CH4 fluxes and environmental variables [soil temperature (T-soil), water table depth (WtD) and active layer (AL) thickness] were established for different temporal and spatial scales. The relationship between in situ WtD and remotely sensed NDWI was also studied. The regression models were combined and evaluated against in situ CH4 fluxes. The models including NDWI as the input data performed on average slightly better [root mean square error (RMSE) = 1.56] than the models without NDWI (RMSE = 1.67), and they were better in reproducing CH4 flux variability. The CH4 flux model that performed the best included exponential relationships against temporal variation in T-soil and AL, an exponential relationship against spatial variation in WtD and a linear relationship between WtD and remotely sensed NDWI (RMSE = 1.50). There were no trends in modelled CH4 flux budgets between 1997 and 2010. Hence, during this period there were no trends in the soil temperature at 10 cm depth and NDWI