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ほとんどの脊椎動物細胞は、接着培養と呼ばれる単層として基板に付着してインビトロで増殖します。 細胞の増殖に使用されるフラスコとプレートは、細胞の付着を促進するために化学処理されています。 ただし、造血細胞などのいくつかの細胞タイプは懸濁液中で増殖できます。 付着培養とは対照的に、懸濁培養は、マグネテ…
細胞培養は、実験室で真核細胞を成長させる技術です。
これは、自然環境外の細胞の生理機能を研究するためのモデルシステムを提供します。
組織サンプルの細胞を培地で直接培養する場合、得られた細胞培養物は初代培養と呼ばれます。
このような細胞は、成長を助けるために、接着培養か懸濁培養かに応じて正しい培養器、最適な温度、アミノ酸、ビタミン、塩、成長因子などの必須栄養素を提供できる適切な増殖培地、pH緩衝システムなど、人工的に制御された条件が必要です。
初代細胞接着培養物が増殖するにつれて、それは徐々に培養皿の全表面積を占めるようになる。
この段階では、細胞をプロテアーゼとトリプシン-EDTAなどのキレート剤の溶液で処理して、細胞-基質および細胞-細胞相互作用を緩め、単一細胞を得る必要があります。
その後、これらの細胞の少数を、新鮮な増殖培地を含む新しいディッシュに継代培養して、継続的な増殖を促進することができます。このような継代培養細胞は、二次培養物を形成する。
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Q1: What is the difference between primary and secondary cell cultures?
Primary cultures are eukaryotic cells grown directly from tissue samples in culture medium. As primary adherent cultures multiply and occupy the entire dish surface, cells must be treated with protease and chelating agents like Trypsin-EDTA to obtain single cells. A small number of these cells are then subcultured into fresh medium, forming secondary cultures that continue growing.
Q2: What are the key components of a growth medium for mammalian cell culture?
Growth media contain amino acids, vitamins, inorganic salts, and glucose as a carbon source. Fetal bovine serum is added as a source of growth factors, hormones, lipids, and minerals. Antibiotics prevent microbial contamination, while buffering systems like sodium bicarbonate maintain pH at 7.4. A pH indicator such as phenol red shows pH changes in the culture.
Q3: How do adherent and suspension cultures differ in their growth requirements?
Adherent cultures grow as monolayers attached to chemically treated flasks and plates. Suspension cultures, such as hematopoietic cells, grow in non-treated cultureware and require magnetic stirrers or spinner flasks to agitate the media. Both culture types need optimal temperature, suitable growth medium, and pH buffering systems for proper development.
Q4: What role do plant growth hormones play in plant cell culture?
Plant growth hormones, specifically auxins and cytokinins, control tissue development in plant cell cultures. A balanced ratio of these hormones produces undifferentiated cells called callus. By altering the hormone ratio, the callus can be differentiated into roots or shoots, generating a complete plant from the explant tissue.
Q5: What conditions must be maintained in an incubator for optimal mammalian cell growth?
Mammalian cells require an optimal temperature of 37°C and a CO2 concentration of 5% in the incubator. The growth medium pH is maintained at 7.4 using buffering systems with sodium bicarbonate and exogenous CO2. These controlled conditions, combined with aseptic culturing protocols, ensure proper cell growth and prevent microbial contamination.
Q6: How are plant cell cultures used in agricultural and conservation applications?
Plant cell cultures produce improved hybrid plants and conserve endangered plant species. Explant cultures are also used in large-scale production of plant-derived products. Plant tissue, known as explant, is cultured in nutrient medium containing plant growth hormones, micronutrients, and a carbon source under controlled temperature, light intensity, and photoperiod conditions.
Q7: Why is Trypsin-EDTA treatment necessary when subculturing adherent cells?
Trypsin-EDTA is a protease and chelating agent solution that loosens cell-substrate and cell-cell interactions in adherent cultures. As primary cultures multiply and occupy the entire dish surface, this treatment is essential to obtain single cells for subculturation. The dissociated cells can then be transferred to fresh growth medium to establish secondary cultures.