404 Not Found
Multicolor fluorescence images of HeLa cells fixed with 4% formaldehyde followed by incubation with mouse tubulin antibody GxM IgG-iFluor 488 conjugates (Green). Cells were stained with Phalloidin-iFluor® 647 Conjugate (Red) following product protocol and incubated with DAPI (Blue) before imaging.
Both internal and external stimuli can act with and alongside the cytoskeleton to affect local mechanical properties and cellular behavior. Cytoskeletal dysregulation has been found in various types of cancers and is known to influence tumor formation, along with neurodegenerative diseases, autoinflammation, conditions involving muscular atrophy, and immunodeficiencies. Due to the variable ability of the cytoskeletal in relation to cellular processes, understanding pathways may be crucial to identifying underlying causes of disease. Because of this, much research has been focused on how cytoskeletal networks generate, transmit, and respond to mechanical signals over both short and long durations of time. Such research dedicated to cytoskeletal structures may provide insight into how these cellular structures function as epigenetic determinants of cell shape, purpose, and fate.
Analysis of the Three Major Components of the Cytoskeleton
Fluorescence image of HeLa cells fixed with 4% formaldehyde then stained with Cell Navigator® F-Actin Labeling Kit *Red Fluorescence* in a Costar black 96-well plate. Cells were labeled with iFluor® 594-Phalloidin (Red) and nuclei stain DAPI (Blue), respectively. Cell endoplasmic reticulum (ER) was stained with ER Green™ (Green) before fixation.
Tubulin
One major component of the cytoskeleton are microtubules, also known as tubulin. Tubulin tends to grow out from the centrosome to the plasma membrane, though in nondividing cells tubulin networks radiate out from the centrosome to provide the structural organization of the cytoplasm and help compartmentalize organelles. Tubulin also helps chromosomes move during cell division and it is the founding component of centrioles, cilia, and flagella.
For analysis, anti-tubulin antibodies, specifically anti-⍺ tubulin, anti-ꞵ I-IV, and anti-γ tubulin antibodies, are commercially available for use in techniques relating to ELISA, flow cytometry, immunohistochemistry, immunoprecipitation, Western blot, immunocytochemistry, and immunofluorescence. Additionally, green and red fluorescent proteins (GFP, RFP) are commonly used for imaging and analysis. However numerous types of fluorescent dyes and probes exist for quantification of tubulin through fluorescent microscopy and similar techniques.
Actin
Another constituent of the cytoskeleton are microfilaments, also known as actin. Networks of actin filaments are normally found beneath the cell cortex, which is the meshwork-like assembly of membrane-associated proteins that support and reinforce the plasma membrane. Actin allows the cells to morph into, and hold, specialized shapes and cell architectures. Actin is usually involved in cytokinesis, muscle contraction, and cell movement. Actin normally can be found in two distinct structures; G-actin has a globular structure, whereas f-actin is filamentous. Common labeling antibodies used by researchers include anti-F actin, anti-nexillin, anti-⍺ actin, and anti-ꞵ actin. Phalloidin conjugates are commonly used as fluorescent experimental markers, though like tubulin, various fluorescent probes and dyes exist for diverse analysis.
Table 1. iFluor® Phalloidin Selection Guide For Phalloidin-iFluor® Conjugates
Conjugate ▲ ▼ | Mol. Wt. ▲ ▼ | Ex/ Em (nm) ▲ ▼ | Filter Set ▲ ▼ | Extinction Coefficient¹ ▲ ▼ | Quantum Yield ▲ ▼ | Unit Size ▲ ▼ |
Phalloidin-iFluor® 350 | ∼1300 | 344/448 | DAPI | 20,000 | 0.95 | 300 Tests |
Phalloidin-iFluor® 405 | ∼1400 | 402/425 | DAPI | 37,000 | 0.91 | 300 Tests |
Phalloidin-iFluor® 488 | ∼1900 | 491/516 | FITC | 75,000 | 0.9 | 300 Tests |
Phalloidin-iFluor® 514 | ∼1800 | 527/554 | TRITC | 80,000 | 0.83 | 300 Tests |
Phalloidin-iFluor® 532 | ∼1800 | 543/563 | TRITC | 90,000 | 0.68 | 300 Tests |
Phalloidin-iFluor® 555 | ∼1300 | 556/569 | TRITC | 100,000 | 0.64 | 300 Tests |
Phalloidin-iFluor® 594 | ∼1600 | 587/603 | Texas Red | 180,000 | 0.53 | 300 Tests |
Phalloidin-iFluor® 633 | 1703.99 | 638/652 | Texas Red | 250,000 | 0.29 | 300 Tests |
Phalloidin-iFluor® 647 | 1632.87 | 654/669 | Cy5 | 250,000 | 0.25 | 300 Tests |
Phalloidin-iFluor® 680 | ∼2000 | 683/700 | Cy5.5 | 220,000 | 0.23 | 300 Tests |
Intermediate Filaments
Lastly, intermediate filaments make up the third major cytoskeletal component. The function of intermediate filaments is primarily mechanical. They are less dynamic in function than actin or tubulin and are not directly involved in cell movement. Intermediate filaments commonly provide strength and support in tandem with tubulin, which is fragile alone. Intermediate filaments can be specific to cell species and can exist, for example, as neurofilaments, desmin filaments, or keratins. Intermediate filaments can be found in a wide range of cell types, for instance as vimentin filaments and lamins, and are non-polar as compared to actin and tubulin. Due to their structure and functional diversity, antibody-based methods are usually the route to go when wanting to assess and analyze intermediate filaments.
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Product Ordering Information
Table 2. Ordering Info for Actin Products
Cat# ▲ ▼ | Product Name ▲ ▼ | Unit Size ▲ ▼ |
5301 | Phalloidin *CAS#: 17466-45-4* | 1 mg |
5302 | Phalloidin Amine | 100 ug |
5303 | Phalloidin-PEG4-DBCO | 100 ug |
23100 | Phalloidin-AMCA Conjugate | 300 Tests |
23101 | Phalloidin-Fluorescein Conjugate | 300 Tests |
23102 | Phalloidin-Tetramethylrhodamine Conjugate | 300 Tests |
23103 | Phalloidin-California Red Conjugate | 300 Tests |
23110 | Phalloidin-iFluor® 350 Conjugate | 300 Tests |
23111 | Phalloidin-iFluor® 405 Conjugate | 300 Tests |
23115 | Phalloidin-iFluor® 488 Conjugate | 300 Tests |
Table 3. Available Classic Dye-Labeled Phalloidin Conjugates.
Conjugate ▲ ▼ | Mol. Wt. ▲ ▼ | Ex/ Em (nm) ▲ ▼ | Filter Set ▲ ▼ | Extinction Coefficient¹ ▲ ▼ | Quantum Yield² ▲ ▼ | Unit Size ▲ ▼ | Cat No. ▲ ▼ |
Phalloidin-AMCA Conjugate | ∼1000 | 346/434 | DAPI | 19000 | Not Determined | 300 Tests | 23100 |
Phalloidin-Fluorescein Conjugate | ∼1100 | 498/517 | FITC | 80000 | 0.79 | 300 Tests | 23101 |
Phalloidin-Tetramethylrhodamine Conjugate | ∼1300 | 552/578 | TRITC | 90000 | Not Determined | 300 Tests | 23102 |
Phalloidin-California Red Conjugate | ∼1000 | 592 | 609 | 100000 | Not Determined | 300 Tests | 23103 |
Table 4. F-actin Labeling Kits
Cat# ▲ ▼ | Product Name ▲ ▼ | Unit Size ▲ ▼ |
22660 | Cell Navigator® F-Actin Labeling Kit *Blue Fluorescence* | 500 Tests |
22661 | Cell Navigator® F-Actin Labeling Kit *Green Fluorescence* | 500 Tests |
22663 | Cell Navigator® F-Actin Labeling Kit *Orange Fluorescence* | 500 Tests |
22664 | Cell Navigator® F-Actin Labeling Kit *Red Fluorescence* | 500 Tests |
Table 7. Anti-tubulin Antibodies
Cat# ▲ ▼ | Product Name ▲ ▼ |
8C0379 | Tubulin α Antibody |
8C0380 | Tubulin β Antibody |
8C0381 | Tubulin γ Antibody |
V103080 | Purified Mouse Anti-human/mouse/pig α/β-Tubulin dimer Antibody *TU-08, monoclonal* |
V103085 | Purified Mouse Anti-human/mouse/rat α/β-Tubulin dimer Antibody *TU-10, monoclonal* |
V103100 | Purified Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-01, monoclonal* |
V103105 | Purified Mouse Anti-human/mouse/rat α-Tubulin Antibody *TU-16, monoclonal* |
V103110 | Purified Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-02, monoclonal* |
V103115 | Biotin Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-01, monoclonal* |
V103120 | FITC Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-01, monoclonal* |