The karyotyping system Ikaros handles also chromosomes from plants and animals, and has an integrated karyogram form editor.
The rodent erythrocyte micronucleus assay can be completely automated with Metafer MetaCyte. Imaging automation of this test is OECD compliant.
The Comet assay can be either automatically analyzed with CometScan, or interactively with CometImager.
With VSlide virtual slides of highest quality are prepared - automatically, flexible, and easy.
MetaCyte automatically detects sperm cells in forensic samples. Position data, an image, and reliablity values are stored for further inspection.
Toxicology, Mutation Research, and Radiation Biology
Automated Assessment of DNA Damage
If large samples are to be analyzed, automation is always a desired feature. This holds especially for quantitative assays commonly used in genotoxicity, mutation research and biological dosimetry. But automation has another advantage: exact settings and well established routines allow for direct comparison of results, and minimize any biases caused by misinterpretation of images.
Metafer is the powerful tool for dose-response analyses - fast to react quickly to unforeseen events (e.g. for radiation dosimetry), reliable to guarantee stable conditions in GLP labs (e.g. in preclinical genotoxicity studies), sensitive to detect even subtle responses (e.g. for environmental mutagenicity tests) and flexible with a full tool box of analysis algorithms (e.g. in mutation research labs).
Any Metafer machine works in a GLP compliant way, providing multi-level user management, audit trails, and encryption of data. Due to flexible architecture all assays can be analyzed on the same system, and results data can be passed to analysis stations connected to the main system. A highly flexible and powerful reporting interface is capable to process and summarize the data for printing, storage, or export. All results are automatically stored, and can be re-visited later - even each single target cell or object is stored as gallery image together with the evaluated data.
Chromosomal Aberration Test
In contrast to many other mutagenicity test the chromosomal aberration test requires a high level of user interaction. It therefore becomes very important to free the researcher from tedious and error prone tasks, such as finding metaphases on the slide, acquiring images, and recording and storing data.
In biological dosimetry, e.g. after a radiation accident, there is probably not enough time to analyze the aberrations in cells of the victims manually. Metafer, with the fast metaphase finder MSearch, AutoCapt, and the revolutionary software for automated dicentric chromosome analysis DCScore, was proven to provide a streamlined solution to this problem.
Metafer MSearch does all this, and it does much more. A typical Giemsa stained slide with metaphases is scanned in less than 3 minutes, and the system is capable to switch automatically to high magnification image acquisition - of course after applying immersion oil to each slide. Images captured are subsequently exported to be analyzed on any workstation in the network. With the Metafer Review software package it is possible to record aberration data in the customizable scoring sheet, and to print or export highly flexible reports summarizing the aberration data.
|The software for automated dicentrics scoring DCScore detects, separates, and counts dicentric chromosomes in metaphases acquired by AutoCapt - extremely fast and proven to be highly reliable.|
But Metafer can do more: with the optional security software upgrade the system becomes fully GLP compliant, and audit trails, multi-level password management, and data encryption is implemented. Blind studies can be conveniently designed with the integrated module to manage aberration studies: the administrator defines the number of experiments, the doses per experiment, and the number of slides per dose. Subsequently users can be assigned to the study, and the slide names are automatically encrypted. Scorers will only see a neutral, 4-digit number code for each slide, thus avoiding any expectation bias. When all slides are scored the system automatically decrypts the slide names, and the study is closed and ready for reporting. Reports may contain any kind of observed aberration data, mitotic indices (global and slide by slide), and data on scoring time and the user. If slides with clones are used, MSearch automatically assigns metaphases to the clones, and separates the data accordingly.
Click here to see a video about Metafer MSearch and DCScore used for biological dosimetry.
Oak Ridge Institute for Science and Education (ORISE)
Cytogenetic Biodosimetry Laboratory
P.O. Box 117
Oak Ridge, TN 37831-0117, USA
[...] we propose the use of software for automated dicentric scoring that was tested on victims of an accident in Dakar.
The results obtained with the automatic detection of dicentric chromosomes in a real accident are particularly promising. [...] because the same time is required to score 50 metaphases manually as 1000 metaphases using the ADS method, the triage step is no longer necessary.
A. Vaurijoux et al., 2009
Strategy for population triage based on dicentric analysis.
Micronucleus (MN) tests are used to estimate DNA damage in preclinical tests, for population triages in biological dosimetry, or of course for research. Purpose of any MN study is to evaluate the amount of DNA damage caused by a certain agent or treatment of the cells, based on counting small nucleus-like structures the cells generate from DNA fragments during the first, post-treatment cell division. There are two different MN tests, usually refered to as the in-vitro and the in-vivo test.
The in-vitro MN test involves treatment of cells in culture with the tested agent, and MN are scored in cells which were given opportunity to divide once after the treatment. In order to identify those cells, the cell division is blocked, so that the target cells have two daughter nuclei. This is why the method also is called the cytokinesis-block MN assay. Metafer with the software upgrade MNScore is capable to automatically identify the bi-nucleated cells, and to count the number of MN in each cell. Cells and MN counts are displayed in the image gallery, and any detected bi-nucleated cell can be relocated with a simple click of the mouse. Data is stored automatically and can be summarized in convenient reports, or exported for further analysis.
The in-vivo MN test is done with live rodent animals which are treated with the tested substance (therefore also referred to as rodent erythrocyte MN assay). After some time of incubation, bone marrow is extracted, purified, and erythrocytes are analyzed for the presence of MN. In order to get information about the toxicity of the substance, it is important to evaluate the ratio of premature erythrocytes (PCE) and the mature erythrocyte (NCE) with in the population. Metafer with MetaCyte is acquiring true color Brightfield images using the unique color LED lightsource. Colors of the cells are then analyzed and dynamically assigned to the two subpopulations. MN are scored in both populations, and the ratio between the subpopulations is calculated. All data is summarized in a customizable report, and can be exported to external databases. The in-vivo MN test scoring procedure with Metafer Metacyte is fully compliant to the respective OECD guideline.
[...] our findings indicate the ability of the automated system to easily analyze slides with a low density of cells [...].
A. Rossnerova et al. (2009)
The impact of air pollution on the levels of micronuclei measured by automated image analysis.
The international project Multibiodose aims to defining a standard for biological dosimetry in the case of radiation accidents with mass casualties. Workpackage 2 of the project has the aim to validate and adapt the automated peripheral blood lymphocyte micronucleus assay to mass casualty scenarios and to organise training. Recently the group has published a project deliverable (D-N° 2.2) with data obtained with Metafer MNScore. The publication summarizes micronucleus data from several labs. Download here the Multibiodose Deliverable D-N° 2.2.
Comet Assay (Single Cell Gel Electrophoresis Assay)
(CometScan and CometImager)
The Comet assay, also known as single cell gel electrophoresis (SCGE) assay, is a technique to detect DNA damage and repair in individual cells. If the DNA of the cells was damaged, there will be short broken DNA strands (fragments), which migrate faster and further through the gel than larger, unfragmented pieces. As a result, a damaged cell appears like a comet, with the DNA fragments forming the comet tail. The size and intensity of the tail is directly proportional to the amount of DNA damage, and can be expressed in parameters like the tail moment or the percentage of DNA in tail. It is crucial to use image analysis for the Comet assay, since precise quantification of head and tail relationship requires detailed identification and analysis of the respective image areas. The Comet assay systems of MetaSystems provide the tools for Comet assay analysis in a very convenient and handy manner.
The interactive stand-alone system CometImager is compatible to any microscope with fluorescence lamp (camera adaptor required). With its convenient analysis screen CometImager achieves an unrivaled speed for manual Comet assay analysis. Images are analyzed automatically after defining the region of interest, and thresholds between head and tail, and cell and background, are automatically obtained based on the user settings. Data is stored and displayed in a table, which can be either printed or exported for further analysis.
CometScan is a software upgrade for the versatile slide scanning platform Metafer. It offers the same flexibile analysis parameters like CometImager, however, it additionally finds comets automatically and unattended on up to 80 slides per run (with the optional SlideFeeder). CometScan is also capable to do multiple image exposures in order to increase the contrast of the final, superimposed image. This method guarantees best results even when head and tail are highly different in intesity.
The automatic CometScan module, software for the multipurpose scanning platform Metafer [...], offers the possibility of completely unattended evaluation of comet preparations. Comet analysis is performed automatically and the distinction between head and tail of the comet is made according to threshold parameters which can be defined by the user. [...] A complete Comet assay from start to results can be performed for several samples within one working day.
F. Verbeek et al. (2008)
Automated Detection Of Irradiated Food With The Comet Assay. Radiation Protection 128(4)
Ames II and Ames MPF Assay
The Ames II / Ames MPF test (based on the method of Xenometrix AG, Basel, Switzerland) is widely used to assess the mutagenic and toxic potential of compounds. Since cancer is often linked to DNA damage, the test also serves as a quick assay to estimate the carcinogenic potential of a compound. Furthermore a positive test can adduce evidence of the toxicity of compounds.
The test uses bacteria carrying DNA mutations in genes involved in the synthesis of the amino acid histidine. Bacteria with this mutation require an external histidine source for growth, since they lost the capability to synthesize the amino acid on their own. The Ames II and Ames MPF assays test the ability of the potential mutagen to cause a reversion of the known mutation. Such a reversion enables the bacteria to grow on a histidine-free medium. The Ames II and Ames MPF assays are modernized versions of the original Ames test, using liquid culture instead of agar plates. The assays are done on 384-well micro titer plates and have a colorimetric read-out, which can be automatically analyzed by Metafer MetaCyte.
Fixed quantities of bacteria are exposed to 6 concentrations of a test agent as well as to a positive and to a negative control. After incubation cultures are diluted in pH indicator and distributed into 48 wells of the 384-well plate. Within two days, cells that have regained the ability to produce histidine will grow into colonies. Metabolism of the bacterial colonies reduces pH of the medium, thus resulting in a color change of the respective well. The number of wells containing reverted colonies are counted for each dose and compared to a zero dose (solvent) control. An increase in the number of reverted colonies upon exposure to test agents relative to the zero dose controls indicates that the substance is mutagenic in the Ames II / Ames MPF assay.
Metafer MetaCyte captures all 384 wells of one plate within approximately 2 minutes using the high speed color camera CoolCube 1c (alternatively a monochrome camera like the CoolCube 1m and the MetaLED color illumination can be used). Analysis is done in real-time during the scan. Each single well is interpreted either positive or negative, giving the user the opportunity to change automatic scores in case of ambiguous results. Printed results contain color images of each well resulting in a complete overview of the 384 well micro plate. Furthermore a table summarizes the number of positive wells per test group. For complete compatibility to the calculation sheet provided by Xenometrix, Metafer is also capable to export the search results.
Handling of micro well plates by the new SlideFeeder x80 is fully supported. Special micro well frames can hold one plate per frame. 8 frames fit into one magazine resulting in a total capacity of 88 micro well plates when using the maximum number of 11 magazines. The SlideFeeder x80 loads the plates fully unattended, and analysis of new micro well plates is done without any further interaction by the user. Usage of Metafer MetaCyte for Ames II / Ames MPF assays facilitates a reliable and unvarying analysis standard and provides the basis for truly comparable results between different studies. All results are completely traceable and documented by high quality color images of each single well.
gamma-H2AX Foci Analysis
Phosphorylated H2AX (gamma-H2AX) is widely used as a marker to detect formation and repair of DNA double strand breaks (DSB). An antibody to gamma-H2AX reveals nuclear foci at the site of DSBs which are clearly visible in the microscope. gamma-H2AX foci formation can be used as a sensitive biological dosimeter and potentially helps to understand important biological processes, human diseases, and individual variations in radiation sensitivity.
Metafer MetaCyte is the ideal tool to automate the quantification of gamma-H2AX foci in cell nuclei. Due to the unique classifier concept scoring standards can be well defined, thus, providing a reproducibility that is not given for manual foci counting. Foci are captured from different microscopic focus planes to guarantee that their 3D dispersion within the nucleus is considered. The total foci number per cell is automatically measured. An image of each nucleus is stored in the gallery, associated with the coordinates of the respective nucleus on the slide. After the search the user can easily inspect the gallery images and, if required, re-locate the nucleus under the microscope.