Techniques de Culture Cellulaire

Culture Cellulaire et Modèles Biologiques

• Cellules Adhérentes: One of two main types of animal cells used in culture to study biological processes. These cells adhere to the container walls and need to be anchored to survive.

• Cellules en Suspension: The other main type of animal cells in culture. These cells float freely in the medium and proliferate without attachment to a surface.

Techniques de Culture Cellulaire

• Centrifugation Différentielle: A technique used to separate supernatant from cell pellet based on density and size differences.

• Limites de la centrifugation différentielle: This technique has limitations. Particles of large size and low density sediment at the same rate as small particles with high density.

Conditions de Culture Cellulaire Animale

• Stérilité: Crucial for preventing contamination by bacteria or microorganisms during animal cell culture.

• Dioxygène: Oxygen is necessary for animal cell culture.

• Température: Optimal temperature is 37°C.

• Humidité: 85-95% humidity is crucial to limit water evaporation.

• CO2: Carbon dioxide levels are maintained at 5% to regulate pH between 7.2 and 7.4.

• Milieu de Culture: A rich medium containing water, salts, carbon sources, amino acids, and fatty acids is needed for successful animal cell culture.

Cellules HeLa

• Célèbres: The HeLa cell line, derived from a cervical cancer tumor in 1951, is famous for revolutionizing medical research, but also raises ethical questions.

Sphéroïdes et Organoïdes

• Sphéroïdes: Self-organized cell aggregates, typically 50–500 µm in size, formed within 2–3 days. Made from various cell types, including co-cultures.

• Organoïdes: Complex three-dimensional structures developed from stem cells and/or other cells, mimicking the structure and function of specific tissues or organs.

Microscopie

• Résolution: The minimum distance between two distinct points visible under the microscope. The resolution of the human eye is 100µm.

• Formule de résolution: (0.61 x λ) / (n x sin(θ))

• Microscopie à contraste de phase: A technique that visualizes transparent and living cells without staining, using differences in refractive index.

• Microscopie à fluorescence: A technique that allows for visualization of specific molecules within a sample using fluorescent probes.

Détection des protéines

• ELISA: An enzyme-linked immunosorbent assay is a common method used in laboratories to detect the presence of antigens (e.g., proteins) or antibodies in a sample.

• Immunoprécipitation: Isolates a specific protein from a mixture using antibodies.

• Co-immunoprécipitation: Isolates a target protein and proteins that interact with it.

• Dot Blot: A simplified technique to detect biomolecules (DNA, RNA, and proteins). Samples are deposited as dots onto a membrane and then detected using specific probes.

Détection des Acides Nucléiques

• Électrophorèse sur gel d'agarose: A laboratory technique used to separate DNA, RNA or protein molecules based on size and charge.

• Southern Blot: Detects specific DNA sequences using labeled probes.

Protéines Dynamiques et Localisation

• GFP (Green Fluorescent Protein): A useful tool to label and track proteins in living cells.

• FRAP (Fluorescence Recovery After Photobleaching): A technique used to measure the mobility and dynamics of proteins or RNAs in live cells.

Fractionnement Cellulaire

• Centrifugation: A method used to separate cell components based on their density and size in a centrifuge.

• Gradient de densité: A centrifugation technique that separates cells or organelles based on differences in their density.

Microscopie Confocale

• Fluorescence parasitique: Noise from out-of-focus light, causing blurry or unclear confocal images.

• Microscopie confocale: Improves resolution by eliminating out-of-focus light, resulting in sharper images.

• CLEM (Correlated Light and Electron Microscopy): A technique that combines information obtained using light microscope and electron microscope techniques. Allows researchers to precisely correlate high-quality images at both the light and electron microscopic levels to investigate cell structures and protein localization, for example.

Testez vos connaissances sur les techniques de culture cellulaire en biologie. Ce quiz explore les différents types de cellules, notamment les cellules adhérentes et en suspension, ainsi que les méthodes de culture et les conditions essentielles pour une culture réussie. Préparez-vous à évaluer votre compréhension des concepts fondamentaux de la culture cellulaire animale.