Nous tenons à remercier Lisa Schneper et Katrin Duevel pour leurs idées dans le développement de ce dosage.

<ol><li> Mettez 200ul de cultures de plus en plus d&#39;intérêt sur les plaques supports synthétiques avec les conditions de famine requis (SC avec 2% de glucose par rapport SC avec 0,2% de glucose, par exemple) Si la densité des cultures sont trop différentes les unes des autres, d&#39;ajuster le nombre de cellules par culture 200ul de sorte que chaque goutte a à peu près la même quantité de cellules. </li><li> Assurez-vous de tenir des registres de qui tombent sur les plaques est où la culture. </li><li> Gardez le couvercle de la plaque entrouverte et laisser soit à température ambiante ou à 30 ° C jusqu&#39;à ce que des gouttes sont à sec. </li><li> Sceau plaques avec du parafilm et pellicule plastique (facultatif) et laisser à 30 ° C pendant 3-7 jours. </li><li> Document de la croissance des cellules sur des plaques (par balayage, de prendre une photo numérique, etc) </li><li> Laver les cellules hors de la surface de la gélose avec de l&#39;eau à haute pression (de préférence de l&#39;eau DI) pendant environ une minute en prenant soin de ne pas lever agar et le changement d&#39;orientation. </li><li> Débarrassez-vous de l&#39;excès d&#39;eau en tapant plaques sur du papier absorbant et les laisser ouvertes pour sécher. </li><li> Une fois les plaques sont sèches documents d&#39;adhérence sur chaque assiette (par numérisation ou de prendre des photos numériques) </li><li> Cellules avec un doigt ganté, frottez doucement hors forment la surface de l&#39;agar sous l&#39;eau courante pendant environ une minute. </li><li> Sécher les plaques comme avant. </li><li> Si vous utilisez un champ de dissection, retirer l&#39;aiguille avant de placer les plaques sur la plateforme de microscopie. </li><li> L&#39;invasion de documents avec un grossissement de 10x ou 40x. Assurez-vous de se concentrer sur la partie du milieu de chaque cercle, les bords seront trop de monde pour voir les morphologies des cellules individuelles. Les bords peuvent indiquer le niveau de croissance filamenteuse et peuvent être documentées pour référence future. Numérisation ou de prendre une photo numérique de toute la plaque peut également être utile. </li></ol>

<ol>
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Les cellules de levure modes d&#39;affichage différents de différenciation en fonction de la disponibilité des nutriments et des conditions environnementales, y compris la formation de spores dans des conditions de famine et le stress, la filamentation sous diverses contraintes en éléments nutritifs, et de floculation. Levures différentes, y compris S. cerevisiae et C. albicans, peuvent également être trouvés dans les biofilms formés par un ensemble diversifié de micro-organismes. Bien qu&#39;il y ait une certaine corrélation av...

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<td>Moticam 350</td>
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<td>discontinued (new model: Moticam 352)</td>
<td>A relatively cheap camera that attaches to eye pieces of microscopes and captures digital images for PC or Mac.</td>
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assay for adhesion and agar invasion in s. cerevisiae

Les levures sont trouvés dans des biofilms naturels, où de nombreux microorganismes colonisent les surfaces. Dans les milieux artificiels, tels que les surfaces des objets artificiels, les biofilms peuvent réduire la productivité industrielle, détruire les structures, et menacent la vie humaine. 1-3 sur l&#39;autre côté, en exploitant la puissance des biofilms peuvent aider à nettoyer l&#39;environnement et générer de l&#39;énergie durable. 4-8 La capacité de S. cerevisiae à coloniser les surfaces et de participer à des biofilms complexes a été largement ignorée jusqu&#39;à ce que la redécouverte de la différenciation des programmes déclenchés par diverses voies de signalisation et les signaux environnementaux dans cet organisme. 9, 10 L&#39;intérêt continue en utilisant S. cerevisiae comme organisme modèle pour comprendre l&#39;interaction et de convergence des voies de signalisation, tels que le Ras-PKA, Kss1 MAPK et Hog1 voies osmolarité, rapidement placé S. cerevisiae dans la jonction du biofilm biologie et la recherche de transduction du signal. 11-20 à cette fin, la différenciation des cellules de levure en longues adhésif, filaments pseudohyphal est devenu une lecture commode pour l&#39;activation des voies de transduction du signal lors de différents changements de l&#39;environnement. Toutefois, la filamentation est un ensemble complexe de phénotypes, ce qui rend dosant pour elle comme si elle était un phénotype simples trompeuse. Dans la dernière décennie, plusieurs tests ont été adoptées avec succès des études de biofilm bactérien à la recherche de levures, telles que la formation des dosages MAT pour mesurer la propagation des colonies sur agar mou et coloration au cristal violet à mesurer quantitativement l&#39;adhérence à la surface cellulaire. 12, 21 Cependant, il ya eu une certaine confusion dans les analyses développées pour évaluer qualitativement les phénotypes adhésif et envahissante de la levure dans l&#39;agar. Ici, nous présentons une méthode simple et fiable pour évaluer la qualité adhésive et envahissantes de souches de levure faciles à comprendre des mesures pour isoler l&#39;évaluation de l&#39;adhérence de l&#39;évaluation d&#39;invasion. Notre méthode, adoptée par les études précédentes, 10, 16 implique des cellules en croissance dans des milieux liquides et le placage sur le traitement différencié des conditions de nutriments pour la croissance des grandes taches, que nous avons ensuite laver à l&#39;eau pour évaluer l&#39;adhérence des cellules et frottez complètement hors de la surface de la gélose pour évaluer l&#39;invasion dans l&#39;agar-agar. Nous éliminons le besoin de stries sur gélose cellules, ce qui affecte l&#39;invasion des cellules dans la gélose. En général, nous avons observé que les souches haploïdes qui envahissent agar sont toujours adhésif, mais pas toutes les souches adhésive peut envahir gélose. Notre approche peut être utilisée en conjonction avec d&#39;autres dosages soigneusement disséquer les étapes de différenciation et les exigences de la transduction du signal de la levure, la différenciation, le quorum sensing et la formation de biofilm.

Watch this Scientific Journal Video about Assay for Adhesion and Agar Invasion in S. cerevisiae at JoVE.com

Assay for Adhesion and Agar Invasion in S. cerevisiae

Nous décrivons un test qualitatif pour l&#39;adhésion de la levure et l&#39;invasion d&#39;agar comme une mesure de la différenciation invasive et pseudohyphal. Ce test simple peut être utilisé pour évaluer le phénotype invasif de divers mutants ainsi que les indices des effets environnementaux et les voies de signalisation sur la différenciation des levures.

Dosage de l&#39;adhésion et l&#39;invasion Agar chez S. cerevisiae

Yeasts are found in natural biofilms, where many microorganisms colonize surfaces. In artificial environments, such as surfaces of man-made objects, ...

assay-for-adhesion-and-agar-invasion-in-s-cerevisiae

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14.8K vues.  Princeton University. Nous décrivons un test qualitatif pour l'adhésion de la levure et l'invasion d'agar comme une mesure de la différenciation invasive et pseudohyphal. Ce test simple peut être utilisé pour évaluer le phénotype invasif de divers mutants ainsi que les indices des effets environnementaux et les voies de signalisation sur la différenciation des levures.

Vidéo: Assay for Adhesion and Agar Invasion in S. cerevisiae

A high-throughput method to globally study the organelle morphology in S. cerevisiae

High-throughput methods to examine protein localization or organelle morphology is an effective tool for studying protein interactions and can help achieve an comprehensive understanding of molecular pathways. In Saccharomyces cerevisiae, with the development of the non-essential gene deletion array, we can globally study the morphology of different organelles like the endoplasmic reticulum (ER) and the mitochondria using GFP (or variant)-markers in different gene backgrounds. However, incorporating GFP markers in each single mutant individually is a labor-intensive process. Here, we describe a procedure that is routinely used in our laboratory. By using a robotic system to handle high-density yeast arrays and drug selection techniques, we can significantly shorten the time required and improve reproducibility. In brief, we cross a GFP-tagged mitochondrial marker (Apc1-GFP) to a high-density array of 4,672 nonessential gene deletion mutants by robotic replica pinning.  Through diploid selection, sporulation, germination and dual marker selection, we recover both alleles. As a result, each haploid single mutant contains Apc1-GFP incorporated at its genomic locus. Now, we can study the morphology of mitochondria in all non-essential mutant background. Using this high-throughput approach, we can conveniently study and delineate the pathways and genes involved in the inheritance and the formation of organelles in a genome-wide setting.

GFP-fusion proteins are widely used to visualize organelles by confocal microscopy. However, screening for mutations that affect the morphology of organelles generally requires individual mutagenesis and is time consuming. Here, we demonstrate a method to simultaneously incorporate organelle-GFP markers in almost 5,000 non-essential genes in yeast.

Une méthode à haut débit pour étudier la morphologie globalement organite chez S. cerevisiae

High-throughput methods to examine protein localization or organelle morphology is an effective tool for studying protein interactions and can help ...

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Identification of protein complexes with quantitative proteomics in S. cerevisiae

Lipids are the building blocks of cellular membranes that function as barriers and in compartmentalization of cellular processes, and recently, as important intracellular signalling molecules. However, unlike proteins, lipids are small hydrophobic molecules that traffic primarily by poorly described nonvesicular routes, which are hypothesized to occur at membrane contact sites (MCSs). MCSs are regions where the endoplasmic reticulum (ER) makes direct physical contact with a partnering organelle, e.g., plasma membrane (PM). The ER portion of ER-PM MCSs is enriched in lipid-synthesizing enzymes, suggesting that lipid synthesis is directed to these sites and implying that MCSs are important for lipid traffic. Yeast is an ideal model to study ER-PM MCSs because of their abundance, with over 1000 contacts per cell, and their conserved nature in all eukaryotes. Uncovering the proteins that constitute MCSs is critical to understanding how lipids traffic is accomplished in cells, and how they act as signaling molecules. We have found that an ER called Scs2p localize to ER-PM MCSs and is important for their formation. We are focused on uncovering the molecular partners of Scs2p. Identification of protein complexes traditionally relies on first resolving purified protein samples by gel electrophoresis, followed by in-gel digestion of protein bands and analysis of peptides by mass spectrometry. This often limits the study to a small subset of proteins. Also, protein complexes are exposed to denaturing or non-physiological conditions during the procedure. To circumvent these problems, we have implemented a large-scale quantitative proteomics technique to extract unbiased and quantified data. We use stable isotope labeling with amino acids in cell culture (SILAC) to incorporate staple isotope nuclei in proteins in an untagged control strain. Equal volumes of tagged culture and untagged, SILAC-labeled culture are mixed together and lysed by grinding in liquid nitrogen. We then carry out an affinity purification procedure to pull down protein complexes. Finally, we precipitate the protein sample, which is ready for analysis by high-performance liquid chromatography/ tandem mass spectrometry. Most importantly, proteins in the control strain are labeled by the heavy isotope and will produce a mass/ charge shift that can be quantified against the unlabeled proteins in the bait strain. Therefore, contaminants, or unspecific binding can be easily eliminated. By using this approach, we have identified several novel proteins that localize to ER-PM MCSs. Here we present a detailed description of our approach. 

Here we describe a new quantitative proteomics technique for identifying protein complexes in Saccharomyces cerevisiae. In this study, we have used the SILAC method together with affinity purification followed by tandem mass spectrometry to identify with high specificity the binding partners of an ER protein, Scs2p.

Identification des complexes protéiques avec la protéomique quantitative chez S. cerevisiae

Lipids are the building blocks of cellular membranes that function as barriers and in compartmentalization of cellular processes, and recently, as ...

An In vitro FluoroBlok Tumor Invasion Assay

The hallmark of metastatic cells is their ability to invade through the basement membrane and migrate to other parts of the body. Cells must be able to both secrete proteases that break down the basement membrane as well as migrate in order to be invasive. BD BioCoat Tumor Invasion System provides cells with conditions that allow assessment of their invasive property in vitro1,2. It consists of a BD Falcon FluoroBlok 24-Multiwell Insert Plate with an 8.0 micron pore size PET membrane that has been uniformly coated with BD Matrigel Matrix. This uniform layer of BD Matrigel Matrix serves as a reconstituted basement membrane in vitro providing a true barrier to non-invasive cells while presenting an appropriate protein structure to study invasion. The coating process occludes the pores of the membrane, blocking non-invasive cells from migrating through the membrane. In contrast, invasive cells are able to detach themselves from and migrate through the coated membrane. Quantitation of cell invasion can be achieved by either pre- or post-cell invasion labeling with a fluorescent dye such as DiIC12(3) or calcein AM, respectively, and measuring the fluorescence of invading cells. Since the BD FluoroBlok membrane effectively blocks the passage of light from 490-700 nm at &gt;99% efficiency, fluorescently-labeled cells that have not invaded are not detected by a bottom-reading fluorescence plate reader. However, cells that have invaded to the underside of the membrane are no longer shielded from the light source and are detected with the respective plate reader. This video demonstrates an endpoint cell invasion assay, using calcein AM to detect invaded cells.

An In vitro FluoroBlok Tumor Invasion Assay

This video demonstrates how to measure cell invasion through cell culture inserts using a fluorescence-based methodology.

Une In vitro Essai FluoroBlok invasion tumorale

The hallmark of metastatic cells is their ability to invade through the basement membrane and migrate to other parts of the body. Cells must be able to ...

Agar-Block Microcosms for Controlled Plant Tissue Decomposition by Aerobic Fungi

The two principal methods for studying fungal biodegradation of lignocellulosic plant tissues were developed for wood preservative testing (soil-block; agar-block). It is well-accepted that soil-block microcosms yield higher decay rates, fewer moisture issues, lower variability among studies, and higher thresholds of preservative toxicity. Soil-block testing is thus the more utilized technique and has been standardized by American Society for Testing and Materials (ASTM) (method D 1413-07). The soil-block design has drawbacks, however, using locally-variable soil sources and in limiting the control of nutrients external (exogenous) to the decaying tissues. These drawbacks have emerged as a problem in applying this method to other, increasingly popular research aims. These modern aims include degrading lignocellulosics for bioenergy research, testing bioremediation of co-metabolized toxics, evaluating oxidative mechanisms, and tracking translocated elements along hyphal networks. Soil-blocks do not lend enough control in these applications. A refined agar-block approach is necessary.
Here, we use the brown rot wood-degrading fungus Serpula lacrymans to degrade wood in agar-block microcosms, using deep Petri dishes with low-calcium agar. We test the role of exogenous gypsum on decay in a time-series, to demonstrate the utility and expected variability. Blocks from a single board rip (longitudinal cut) are conditioned, weighed, autoclaved, and introduced aseptically atop plastic mesh. Fungal inoculations are at each block face, with exogenous gypsum added at interfaces. Harvests are aseptic until the final destructive harvest. These microcosms are designed to avoid block contact with agar or Petri dish walls. Condensation is minimized during plate pours and during incubation. Finally, inoculum/gypsum/wood spacing is minimized but without allowing contact. These less technical aspects of agar-block design are also the most common causes of failure and the key source of variability among studies. Video publication is therefore useful in this case, and we demonstrate low-variability, high-quality results.

This video demonstrates a controlled environment approach to study degradation of lignocellulosic plant tissues by aerobic fungi. The ability to control nutrient sources and moisture is a key advantage of agar-block microcosms, but the approach often yields mixed success. We address critical pitfalls to yield reproducible, low-variability results.

Agar-Block microcosmes pour la décomposition des tissus végétaux contrôlés par des champignons aérobie

The two principal methods for studying fungal biodegradation of lignocellulosic plant tissues were developed for wood preservative testing (soil-block; ...

A Fluorescence Microscopy Assay for Monitoring Mitophagy in the Yeast Saccharomyces cerevisiae

Autophagy is important for turnover of cellular components under a range of different conditions. It serves an essential homeostatic function as well as a quality control mechanism that can target and selectively degrade cellular material including organelles1-4. For example, damaged or redundant mitochondria (Fig. 1), not disposed of by autophagy, can represent a threat to cellular homeostasis and cell survival. In the yeast, Saccharomyces cerevisiae, nutrient deprivation (e.g., nitrogen starvation) or damage can promote selective turnover of mitochondria by autophagy in a process termed mitophagy 5-9.
We describe a simple fluorescence microscopy approach to assess autophagy. For clarity we restrict our description here to show how the approach can be used to monitor mitophagy in yeast cells. The assay makes use of a fluorescent reporter, Rosella, which is a dual-emission biosensor comprising a relatively pH-stable red fluorescent protein linked to a pH-sensitive green fluorescent protein. The operation of this reporter relies on differences in pH between the vacuole (pH ~ 5.0-5.5) and mitochondria (pH ~ 8.2) in living cells. Under growing conditions, wild type cells exhibit both red and green fluorescence distributed in a manner characteristic of the mitochondria. Fluorescence emission is not associated with the vacuole. When subjected to nitrogen starvation, a condition which induces mitophagy, in addition to red and green fluorescence labeling the mitochondria, cells exhibit the accumulation of red, but not green fluorescence, in the acidic vacuolar lumen representing the delivery of mitochondria to the vacuole. Scoring cells with red, but not green fluorescent vacuoles can be used as a measure of mitophagic activity in cells5,10-12.

A Fluorescence Microscopy Assay for Monitoring Mitophagy in the Yeast Saccharomyces cerevisiae

A robust approach to monitor the delivery of organelles to the acidic lumen of the yeast vacuole for degradation and recycling is described. The method relies on the specific labeling of target organelles with a genetically encoded dual-emission fluorescence pH-biosensor, and visualization of individual cells using fluorescence microscopy.

Un test microscopie de fluorescence pour Mitophagy surveillance dans la levure<em&gt; Saccharomyces cerevisiae

Autophagy is important for turnover of cellular components under a range of different conditions. It serves an essential homeostatic function as well as a ...

Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model

Studies using the Saccharomyces cerevisiae aging model have uncovered life span regulatory pathways that are partially conserved in higher eukaryotes1-2. The simplicity and power of the yeast aging model can also be explored to study DNA damage and genome maintenance as well as their contributions to diseases during aging. Here, we describe a system to study age-dependent DNA mutations, including base substitutions, frame-shift mutations, gross chromosomal rearrangements, and homologous/homeologous recombination, as well as nuclear DNA repair activity by combining the yeast chronological life span with simple DNA damage and mutation assays. The methods described here should facilitate the identification of genes/pathways that regulate genomic instability and the mechanisms that underlie age-dependent DNA mutations and cancer in mammals.

Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model

Here we describe a set of DNA mutation assays that can be combined with the yeast chronological life span model to study the genes/pathways that regulate or contribute to genomic DNA instability during aging.

Etudier Instabilité génomique fonction de l&#39;âge en utilisant les S. cerevisiae Modèle chronologique Lifespan

Studies using the Saccharomyces cerevisiae aging model have uncovered life span regulatory pathways that are partially conserved in higher eukaryotes1-2. ...

Flow Cytometry-based Purification of S. cerevisiae Zygotes

Zygotes are essential intermediates between haploid and diploid states in the life cycle of many organisms, including yeast (Figure 1) 1. S. cerevisiae zygotes result from the fusion of haploid cells of distinct mating type (MATa, MATalpha) and give rise to corresponding stable diploids that successively generate as many as 20 diploid progeny as a result of their strikingly asymmetric mitotic divisions 2. Zygote formation is orchestrated by a complex sequence of events: In this process, soluble mating factors bind to cognate receptors, triggering receptor-mediated signaling cascades that facilitate interruption of the cell cycle and culminate in cell-cell fusion. Zygotes may be considered a model for progenitor or stem cell function.
Although much has been learned about the formation of zygotes and although zygotes have been used to investigate cell-molecular questions of general significance, almost all studies have made use of mating mixtures in which zygotes are intermixed with a majority population of haploid cells 3-8. Many aspects of the biochemistry of zygote formation and the continuing life of the zygote therefore remain uninvestigated.
Reports of purification of yeast zygotes describe protocols based on their sedimentation properties 9; however, this sedimentation-based procedure did not yield nearly 90% purity in our hands. Moreover, it has the disadvantage that cells are exposed to hypertonic sorbitol. We therefore have developed a versatile purification procedure. For this purpose, pairs of haploid cells expressing red or green fluorescent proteins were co-incubated to allow zygote formation, harvested at various times, and the resulting zygotes were purified using a flow cytometry-based sorting protocol. This technique provides a convenient visual assessment of purity and maturation. The average purity of the fraction is approximately 90%. According to the timing of harvest, zygotes of varying degrees of maturity can be recovered. The purified samples provide a convenient point of departure for "-omic" studies, for recovery of initial progeny, and for systematic investigation of this progenitor cell.

Flow Cytometry-based Purification of S. cerevisiae Zygotes

To purify zygotes of S. cerevisiae, haploid cells of opposite mating type were engineered to express red or green fluorescent proteins, co-incubated to allow zygote formation, and fractionated using a flow cytometry-based protocol. The highly-enriched fraction enables subsequent "-omic" studies, recovery of initial progeny, and systematic investigation of zygote morphogenesis.

Cytométrie en flux à base de purification de<em&gt; S. cerevisiae</em&gt; Zygotes

Zygotes are essential intermediates between haploid and diploid states in the life cycle of many organisms, including yeast (Figure 1) 1. S. cerevisiae ...

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for using FISH to quantify the number of mRNAs in single yeast cells. Cells can be grown in any condition of interest and then fixed and made permeable. Subsequently, multiple single-stranded deoxyoligonucleotides conjugated to fluorescent dyes are used to label and visualize mRNAs. Diffraction-limited fluorescence from single mRNA molecules is quantified using a spot-detection algorithm to identify and count the number of mRNAs per cell. While the more standard quantification methods of northern blots, RT-PCR and gene expression microarrays provide information on average mRNAs in the bulk population, FISH facilitates both the counting and localization of these mRNAs in single cells at single-molecule resolution.

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

This protocol describes an experimental procedure for performing Fluorescence in situ Hybridization (FISH) for counting mRNAs in single cells at single-molecule resolution.

Visualisation et d&#39;analyse de molécules d&#39;ARNm par fluorescence<em&gt; In Situ</em&gt; Hybridation dans<em&gt; Saccharomyces cerevisiae</em

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for ...

Coupled Assays for Monitoring Protein Refolding in Saccharomyces cerevisiae

Proteostasis, defined as the combined processes of protein folding/biogenesis, refolding/repair, and degradation, is a delicate cellular balance that must be maintained to avoid deleterious consequences 1. External or internal factors that disrupt this balance can lead to protein aggregation, toxicity and cell death. In humans this is a major contributing factor to the symptoms associated with neurodegenerative disorders such as Huntington's, Parkinson's, and Alzheimer's diseases 10. It is therefore essential that the proteins involved in maintenance of proteostasis be identified in order to develop treatments for these debilitating diseases. This article describes techniques for monitoring in vivo protein folding at near-real time resolution using the model protein firefly luciferase fused to green fluorescent protein (FFL-GFP). FFL-GFP is a unique model chimeric protein as the FFL moiety is extremely sensitive to stress-induced misfolding and aggregation, which inactivates the enzyme 12. Luciferase activity is monitored using an enzymatic assay, and the GFP moiety provides a method of visualizing soluble or aggregated FFL using automated microscopy. These coupled methods incorporate two parallel and technically independent approaches to analyze both refolding and functional reactivation of an enzyme after stress. Activity recovery can be directly correlated with kinetics of disaggregation and re-solubilization to better understand how protein quality control factors such as protein chaperones collaborate to perform these functions. In addition, gene deletions or mutations can be used to test contributions of specific proteins or protein subunits to this process. In this article we examine the contributions of the protein disaggregase Hsp104 13, known to partner with the Hsp40/70/nucleotide exchange factor (NEF) refolding system 5, to protein refolding to validate this approach.

Coupled Assays for Monitoring Protein Refolding in Saccharomyces cerevisiae

This article describes the use of a firefly luciferase-GFP fusion protein to investigate in vivo protein folding in Saccharomyces cerevisiae. Using this reagent, refolding of a model heat-denatured protein can be monitored simultaneously by fluorescence microscopy and an enzymatic assay to probe the roles of proteostasis network components in protein quality control.

Les analyses couplées pour la surveillance protéines repliement<em&gt; Saccharomyces cerevisiae</em

Proteostasis, defined as the combined processes of protein folding/biogenesis, refolding/repair, and degradation, is a delicate cellular balance that must ...

The Soft Agar Colony Formation Assay

Anchorage-independent growth is the ability of transformed cells to grow independently of a solid surface, and is a hallmark of carcinogenesis. The soft agar colony formation assay is a well-established method for characterizing this capability in vitro and is considered to be one of the most stringent tests for malignant transformation in cells. This assay also allows for semi-quantitative evaluation of this capability in response to various treatment conditions. Here, we will demonstrate the soft agar colony formation assay using a murine lung carcinoma cell line, CMT167, to demonstrate the tumor suppressive effects of two members of the Wnt signaling pathway, Wnt7A and Frizzled-9 (Fzd-9). Concurrent overexpression of Wnt7a and Fzd-9 caused an inhibition of colony formation in CMT167 cells. This shows that expression of Wnt7a ligand and its Frizzled-9 receptor is sufficient to suppress tumor growth in a murine lung carcinoma model.

The soft agar colony formation assay is a method used to confirm cellular anchorage-independent growth in vitro. The goal of this protocol is to illustrate a stringent method for the detection of the tumorigenic potential of transformed cells and the tumor suppressive effects of proteins on transformed cells.

La formation de dosage souple Agar Colony

Anchorage-independent growth is the ability of transformed cells to grow independently of a solid surface, and is a hallmark of carcinogenesis. The soft ...