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Cytoskeleton Structure & Analysis

The cytoskeleton is an interconnected network of filamentous polymers and regulatory proteins that help cells sustain their shape and internal arrangement. The cytoskeleton provides mechanical support that allows cells to conduct essential functions like cell division and movement. It is a dynamic and adaptive structure whose constituent components are in constant flux.

The cytoskeleton has a handful of key functions; to spatially organize and distribute cellular compartments, to connect the cell physically and biochemically to the external microenvironment, and to generate and coordinate forces that enable the cell to move and adjust form. The cytoskeleton also offers the cell the ability to resist deformation from extrinsic forces and aid in the transport of intracellular cargo. 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

Multicolor fluorescence images of HeLa cells
Multicolor fluorescence images of HeLa cells fixed with 4% formaldehyde followed by incubation with 1 ug/mL mouse tubulin antibody GxM IgG-iFluor 488 conjugates (Green). Cells were stained with Phalloidin-iFluor® 647 Conjugate (Red) following product protocol and incubated with 2 uM DAPI (Blue) for 5 min before imaging.
The cytoskeleton is made up of three main components, tubulin, actin, and intermediate filaments, that each work to support the shape of the cell and have specifically associated morphologies and functions. To a lesser extent, the cytoskeleton is also made up of many cytoplasmic proteins and organelles. Roughly 150 proteins alone have been found to contain binding domains to actin. Many of these proteins serve in various regulatory functions, including roles in crosslinking, molecular adhesion, synaptic plasticity, and coordinating signaling cascade. The cytoskeleton also influences binding or inhibition to phospholipids, membrane trafficking, ion transport, and spatial localization of signaling. 


One 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.


Another 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.

Table 1. iFluor® Phalloidin Selection Guide For Phalloidin-iFluor® Conjugates

Mol. Wt.
Ex/ Em (nm)
Filter Set
Extinction Coefficient¹
Quantum Yield
Unit Size
Phalloidin-iFluor® 350∼1300344/448DAPI20,0000.95300 Tests
Phalloidin-iFluor® 405∼1400402/425DAPI37,0000.91300 Tests
Phalloidin-iFluor® 488∼1900491/516FITC75,0000.9300 Tests
Phalloidin-iFluor® 514∼1800527/554TRITC80,0000.83300 Tests
Phalloidin-iFluor® 532∼1800543/563TRITC90,0000.68300 Tests
Phalloidin-iFluor® 555∼1300556/569TRITC100,0000.64300 Tests
Phalloidin-iFluor® 594∼1600587/603Texas Red180,0000.53300 Tests
Phalloidin-iFluor® 6331703.99638/652Texas Red250,0000.29300 Tests
Phalloidin-iFluor® 6471632.87654/669Cy5250,0000.25300 Tests
Phalloidin-iFluor® 680∼2000683/700Cy5.5220,0000.23300 Tests
Phalloidin-iFluor® 700∼3000690/713Cy5.5220,0000.23300 Tests
Phalloidin-iFluor® 750∼3300756/777Cy7275,0000.12300 Tests
Phalloidin-iFluor® 790∼2800786/811Cy7250,0000.13300 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 3. Available Classic Dye-Labeled Phalloidin Conjugates.

Mol. Wt.
Ex/ Em (nm)
Filter Set
Extinction Coefficient¹
Quantum Yield&sup2
Unit Size
Cat No.
Phalloidin-AMCA Conjugate∼1000346/434DAPI19000Not Determined300 Tests23100
Phalloidin-Fluorescein Conjugate∼1100498/517FITC800000.79300 Tests23101
Phalloidin-Tetramethylrhodamine Conjugate∼1300552/578TRITC90000Not Determined300 Tests23102
Phalloidin-California Red Conjugate∼1000592609100000Not Determined300 Tests23103

Table 4. F-actin Labeling Kits

Product Name
Unit Size
22660Cell Navigator® F-Actin Labeling Kit *Blue Fluorescence*500 Tests
22661Cell Navigator® F-Actin Labeling Kit *Green Fluorescence*500 Tests
22663Cell Navigator® F-Actin Labeling Kit *Orange Fluorescence*500 Tests
22664Cell Navigator® F-Actin Labeling Kit *Red Fluorescence*500 Tests

Table 5. Anti-Lamin Antibodies

Product Name
8A0503Lamin A/C (Phospho-Ser392) Antibody
8A8464Lamin A (Phospho-Ser22) Antibody
8B0503Lamin A/C (Ab-392) Antibody
8B8464Lamin A (Ab-22) Antibody
8L0116Lamin A (Cleaved-Asp230) Antibody
8L0117Lamin A (Cleaved-Asp230) Antibody

Table 6. Tubulin Staining Kits

Product Name
Unit Size
23170Cell Navigator® Live Cell Tubulin Staining Kit100 Slides
23171Cell Navigator® Live Cell Tubulin Staining Kit300 Slides

Table 7. Anti-tubulin Antibodies

Product Name
8C0379Tubulin α Antibody
8C0380Tubulin β Antibody
8C0381Tubulin γ Antibody
V103080Purified Mouse Anti-human/mouse/pig α/β-Tubulin dimer Antibody *TU-08, monoclonal*
V103085Purified Mouse Anti-human/mouse/rat α/β-Tubulin dimer Antibody *TU-10, monoclonal*
V103100Purified Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-01, monoclonal*
V103105Purified Mouse Anti-human/mouse/rat α-Tubulin Antibody *TU-16, monoclonal*
V103110Purified Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-02, monoclonal*
V103115Biotin Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-01, monoclonal*
V103120FITC Mouse Anti-human/mouse/pig α-Tubulin Antibody *TU-01, monoclonal*
V103230Purified Mouse Anti-human/mouse/dog βIII-Tubulin Antibody *TU-20, monoclonal*
V103235FITC Mouse Anti-human/mouse/dog βIII-Tubulin Antibody *TU-20, monoclonal*
V103240Purified Mouse Anti-human/mouse/arabidopsis β-Tubulin Antibody *TU-06, monoclonal*
V103245Purified Mouse Anti-human/mouse/rat β-Tubulin Antibody *TU-12, monoclonal*
V103250Purified Mouse Anti-human/mouse/pig β-Tubulin Antibody *TU-13, monoclonal*
V103695Purified Mouse Anti-human/mouse/protozoa γ-Tubulin Antibody *TU-30, monoclonal*
V103700Purified Mouse Anti-protozoa/plants/animals γ-Tubulin Antibody *TU-32, monoclonal*
V103705Purified Mouse Anti-human/mouse/rat γ-Tubulin GCP2 Antibody *GCP2-01, monoclonal*



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