In This Issue
FEATURED NEW PRODUCTS
what it is
how it works
|Chemiluminescent Alkaline Phosphatase ELISA Kit #1: with CSPD® substrate and Sapphire-II™ Enhancer||1,000 assays||C10552|
|Chemiluminescent Alkaline Phosphatase ELISA Kit #2: with CSPD® substrate and Emerald-II™ Enhancer||1,000 assays||C10553|
|Chemiluminescent Alkaline Phosphatase ELISA Kit #3: with CDP-Star® substrate and Sapphire-II™ Enhancer||1,000 assays||C10554|
|Chemiluminescent Alkaline Phosphatase ELISA Kit #4: with CDP-Star® substrate and Emerald-II™ Enhancer||1,000 assays||C10555|
|Chemiluminescent Alkaline Phosphatase ELISA Sampler Kit||1,000 assays||C10556|
what it is
how it works
|Click-iT® EdU Alexa Fluor® 488 Imaging Kit *for 50 coverslips*||1 kit||C10337|
|Click-iT® EdU Alexa Fluor® 594 Imaging Kit *for 50 coverslips*||1 kit||C10339|
|Click-iT® EdU Alexa Fluor® 647 Imaging Kit *for 50 coverslips*||1 kit||C10340|
|Click-iT® EdU Alexa Fluor® 488 HCS Assay *2-plate size*||1 kit||C10350|
|Click-iT® EdU Alexa Fluor® 488 HCS Assay *10-plate size*||1 kit||C10351|
|Click-iT® EdU Alexa Fluor® 594 HCS Assay *2-plate size*||1 kit||C10354|
|Click-iT® EdU Alexa Fluor® 594 HCS Assay *10-plate size*||1 kit||C10355|
|Click-iT® EdU Alexa Fluor® 647 HCS Assay *2-plate size*||1 kit||C10356|
|Click-iT® EdU Alexa Fluor® 647 HCS Assay *10-plate size*||1 kit||C10357|
Image Newly Synthesized RNA Without Antibodies or Radioactivity — Click-iT® RNA Imaging Kits and HCS Assays
what it is
how it works
|Click-iT® RNA Alexa Fluor® 488 Imaging Kit *for 25 coverslips*||1 kit||C10329|
|Click-iT® RNA Alexa Fluor® 594 Imaging Kit *for 25 coverslips*||1 kit||C10330|
|Click-iT® RNA Alexa Fluor® 488 HCS Assay *2-plate size*||1 kit||C10327|
|Click-iT® RNA Alexa Fluor® 594 HCS Assay *2-plate size*||1 kit||C10328|
The ability to measure cytoskeletal disruption is an important aspect of cytotoxicity screening in drug discovery and development. While fluorescent conjugates of phalloidin and anti-tubulin antibodies are popular probes used for measuring cytoskeletal disruption, a mask of the entire cell is also important for both cellular demarcation and to determine cell size. Cellular demarcation enables automated image analysis software to determine where the cytoskeleton of one cell ends and another begins, and cannot be done accurately with a nuclear counterstain alone.
Invitrogen’s HCS CellMask™ stains can be used to measure quantitative differences in cell size resulting from drug treatment. The stains range in fluorescence emission from blue to deep red, allowing researchers flexibility when performing multi-parametric assays for high-content imaging.
- Learn More about CellMask™ Reagents and Other Tools for High-Content Imaging
|The effects of cytochalasin D treatment on HeLa cell size as measured by HCS CellMask™ Blue stain. HeLa cells were treated with DMSO vehicle (left) or 10 µM cytochalasin D (right) for 3 hr before fixation and permeabilization. Samples were then labeled with HCS CellMask™ Blue stain, Alexa Fluor® 488–conjugated phalloidin to visualize filamentous actin (red), mouse anti-α-tubulin IgG detected with Alexa Fluor® 555 goat anti-mouse IgG (green), and TO-PRO®-3 iodide to counterstain nuclei (magenta). The bar graph represents quantitative measurements of cell size as indicated by HCS CellMask™ Blue stain to show the effects of cytochalasin D treatment.|
|HCS CellMask™ Red stain||1 set||H32712|
|HCS CellMask™ Orange stain||1 set||H32713|
|HCS CellMask™ Green stain||1 set||H32714|
|HCS CellMask™ Blue stain||1 set||H32720|
|HCS CellMask™ Deep Red stain||1 set||H32721|
The Countess™ Automated Cell Counter uses trypan blue staining combined with a sophisticated image analysis algorithm to enable accurate cell and viability counts in just 30 seconds. The algorithm also measures the average size of live, dead, and total cells to give you all the data you need from your cell cultures without using a hemocytometer.
Despite being one of the most popular viability stains, trypan blue has recently been recognized as a potentially hazardous chemical. As a result, many labs minimize exposure by working with smaller volumes or lower concentrations of trypan blue. The Countess™ Automated Cell Counter requires only 5 µL of trypan blue and is shipped precalibrated for use with 0.4% trypan blue. By simply and quickly recalibrating the instrument, lower than conventional concentrations of trypan blue (0.1%) can be used for cell counting.
The Countess™ Automated Cell Counter
|Countess™ Automated Cell Counter||each||C10227|
Countess™ Automated Cell Counter Starter Kit
|Countess™ Automated Cell Counter Lab Starter Kit|
(includes 1 cell counter and 101 boxes of slides)
|Countess™ Cell Counting Chamber Slides||50 slides (100 counts)||C10228|
|Countess™ Cell Counting Chamber Slides||500 slides (1,000 counts)||C10312|
|Countess™ Cell Counting Chamber Slides||1,250 slides (2,500 counts)||C10313|
|Countess™ Cell Counting Chamber Slides||2,500 slides (5,000 counts)||C10314|
|Countess™ Cell Counting Chamber Slides||5,000 slides (10,000 counts)||C10315|
A pHrodo™ Dye–based Method for Monitoring the Phagocytic Internalization of Apoptotic Cells
A novel method to determine the engulfment of apoptotic cells by macrophages using pHrodo succinimidyl ester.
Miksa M, Komura H, Wu R et al. (2009) J Immunol Methods 342:71–77.
How can we accurately assay the phagocytosis of apoptotic cells?
A key component of apoptosis is the phagocytic removal of cellular debris that results when cells undergo apoptotic self-termination; this clean-up step is carried out by specialized immune cells such as macrophages and neutrophils. While many methods have been developed to assay the initial binding step of phagocytosis, these methods can lead to overestimation of the extent of internalization. In this report, Miksa and colleagues describe a simple and elegant method for monitoring the internalization step itself, which relies on macrophage-mediated chemical alteration of the internal environment of engulfed particles.
To monitor phagocytosis, target cells (apoptotic thymocytes) were loaded with the pH-sensitive fluorescent dye pHrodo™ Succinimidyl Ester (SE). Upon phagocytic engulfment by macrophages, these target cells are lysed and their contents encounter the acidic environment within the phagosome, causing a dramatic increase in pHrodo™ dye fluorescence. This assay was used to monitor the engulfment of apoptotic thymocytes by FACS flow cytometric analysis in addition to direct observation by fluorescence microscopy.
In addition to showing excellent agreement with previously reported results, the authors accurately characterized the limited phagocytic activity of cells deficient in MFGE8 (a key protein required for phagocytosis), and demonstrated the successful recovery of phagocytic activity upon addition of exogenous MFGE8.
This study represents the first application of this approach to eukaryotic apoptotic cells. The authors suggest that the pHrodo™ dye–based assay may prove useful in future studies of the role of macrophages in apoptosis.
View bibliography reference
- Learn More about pHrodo™ Indicators
|pHrodo™ Succinimidyl Ester (pHrodo™, SE)||1 mg||P36600|
|Free online technical webinars |
You are invited to join us for a series of biweekly technical webinars from the comfort of your desk. The webinars will initially focus on imaging-related applications, but we welcome your feedback for additional topics throughout the course of the year. Upcoming topics will be announced each month via email.
Presentations will last approximately 45 minutes, followed by 15 minutes for live Q&A.
Missed our previous webinars? Find our recorded webinars here!
|Imaging cell division in real time. U2OS cells were transduced with Cellular Lights™ Histone 2B-RFP (red) and Cellular Lights™ MAP4-GFP (green) Cells were kept in a climate-controlled chamber and imaged in McCoy's media with a 40x objective and FITC/TRITC filters. Images were collected every 5 min for 7 hr and 35 min. Time lapse imaging was performed on the DeltaVision® Core microscope. |
Watch the video!
|Cellular Lights™ Histone 2B-RFP||1 kit||C10129|
|Cellular Lights™ MAP4-GFP||1 kit||C10105|
|McCoy’s 5A Medium (modified) (1X), liquid||500 mL||12330031|
Tracking Tumor Metastasis — DQ™ Collagen
Tumor cells release matrix metalloproteinases (MMPs) including collagenases to facilitate the breakdown of various extracellular matrix (ECM) components. This breakdown allows tumor cells to migrate across cell and tissue boundaries—a process known as metastasis. The fluorescein conjugate DQ™ collagen can be used to directly monitor the collagenase activity of tumor cells. This collagen substrate readily self-quenches, but fluoresces upon cleavage. In combination with CellTracker™ dyes, DQ™ collagen can be used for live-cell tracking of cell migration , or for in situ zymography on unfixed cryosections. DQ™ Collagen assays are also amenable to large-scale studies of metastasis inhibitors in drug discovery settings.
1. Sameni et al. (2009) Clin Exp Metastasis 26:299–309.
Interaction of tumor spheroids with stromal fibroblasts results in extensive degradation of type IV collagen. HCT116 human colon carcinoma cells were cocultured with human colon fibroblasts prestained with CellTracker™ Orange in reconstituted basement membrane containing DQ™ collagen, type IV. Extensive proteolysis, resulting in fluorescence of DQ™ collagen IV (green), occurs at the site of interaction between the tumor spheroids and the fibroblasts (orange), with yellow regions denoting areas of overlap. Magnification: 40x. Image courtesy of Mansoureh Sameni and Bonnie Sloane, Wayne State University.
|DQ™ collagen, type IV from human placenta, fluorescein conjugate||1 mg||D12052|
|DQ™ collagen, type I from bovine skin, fluorescein conjugate||1 mg||D12060|
|Geltrex™ Reduced Growth Factor Basement Membrane Matrix||1 mL||12760013|
|CellTracker™ Blue CMAC||5 mg||C2110|
|CellTracker™ Green CMFDA||20 x 50 μg||C7025|
|CellTracker™ Orange CMTMR||1 mg||C2927|
|CellTracker™ Orange CMRA||20 x 50 μg||C34551|
|CellTracker™ Red CMTPX||20 x 50 μg||C34552|
|New Web Resource for Chemiluminescence Assays|
Invitrogen offers a wide spectrum of ultrasensitive assays with a chemiluminescent readout. These assays consistently provide high-intensity signal, low background, high sensitivity, wide dynamic range, and rapid results, and are compatible with multiple assay formats (ELISA, reporter gene, and cAMP) under physiologically relevant conditions. Now it’s easier than ever to find the right chemiluminescence assay for your research.
|Cell and Tissue Analysis Technical Support |
Choose a product area on the Cell and Tissue Analysis Technical Support page to access FAQs, protocols, and troubleshooting assistance.
Browse Online Cell & Tissue Analysis Technical Support
Invitrogen and Zymera Broaden the Use of Qdot® Nanocrystals to Enhance In Vivo Imaging and Biomarker Discovery
Invitrogen has licensed its extensive intellectual property estate related to Qdot® nanocrystal technology to Zymera, a nanobiotechnology company focused on the development of illumination technology for life science research. Zymera will use Qdot® Nanocrystals to create new, self-illuminating quantum dot products to improve in vivo imaging and biomarker discovery, and for the development of new biosensing applications.
Zymera’s novel self-illumination technology uses Bioluminescence Resonance Energy Transfer (BRET) to transfer light from a bioluminescent protein—such as luciferase—directly to quantum dots. First described by the Rao lab at Stanford,1 the resulting BRET dots produce light without an external source of illumination, eliminating autofluorescence background and the need for external light sources, such as lasers. As a result, it is possible to visualize targets deeper in tissue sections or in living animals, and to identify multiple targets simultaneously with a wider variety of detection devices. Zymera expects to combine the technologies to develop new products for tracing blood and lymphatic fluid flow, tracking cells, and detecting biomarkers for use across a range of life science applications.
1. Curr Opin Biotechnol 20:37(2009).
- Learn More about Zymera’s BRET-Qdot® Technology
- Learn More about Qdot® Nanocrystals for In Vivo Applications
Design of the BRET Qdot® conjugate and the BRET Qdot® catalytic reaction. Exposure to the luciferase substrate, coelenterazine, causes the emission of light of peak wavelength 480 nm from the luciferase enzyme. The energy from this reaction couples non-radioactively to the Qdot® acceptor (shown by the green dotted arrows). In this example, the Qdot® nanocrystal emits light in the red to near-infrared regions (655 nm). The Luc8 enzyme has 8 mutations that confer a 200-fold increase of stability in serum and a 4-fold improvement in light output over the native enzyme.
Molecular Probes® The Handbook
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