Thomas Giddings (2011) CIL:16226, Oscillatoria tenuis. CIL. Dataset

The thylakoids of the vegetative cells of the filamentous cyanobacteria, Oscillatoria tenuis, are capable of oxygen-evolving photosynthesis. Freeze-fracture replicas of the vegetative cells revealed the structure of the thylakoids.

The process of freeze-fracture splits memebranes along their hydrophobic interior revealing two complementary fracture faces designated P-face and E-face. Each fracture faces has a population of particles which represent intramembrane proteins or protein complexes.

Oscillatoria cultures were maintained on agar plates. Cells were collected and suspended in 10 mL dH2O, spun at 2,000 g for 10 min in a clinical centrifuge, resuspended in 5 mL dH2O. Added 5 mL 70% glycerol over 1 hr with continuous stirring, spun at 2,000 g for 10 min in a clinical centrifuge. Pellets were placed on copper support discs, frozen in liquid Freon 12 and stored under liquid nitrogen. Replicas were prepared on a Blazers BA 360 freeze-etch unit and examined in a JEOL TEM 100C at 50,000X magnification.

丝状蓝藻Oscillatoria tenuis的营养细胞叶绿体薄膜具备进行氧合光合作用的能力。通过对营养细胞的冷冻断裂复制品进行观察，揭示了叶绿体薄膜的微观结构。冷冻断裂技术通过沿膜的水溶性内部进行分裂，从而暴露出两个互补的断裂面，分别标记为P面和E面。每个断裂面都存在一群颗粒，这些颗粒代表着跨膜蛋白或蛋白复合体。Oscillatoria的培养在琼脂平板上进行。收集细胞并将其悬浮于10毫升去离子水中，在临床离心机中以2,000 g的转速离心10分钟，然后在5毫升去离子水中重新悬浮。将70%的甘油加入其中，并持续搅拌1小时，再次在临床离心机中以2,000 g的转速离心10分钟。将沉淀物置于铜支持圆盘上，用液态Freon 12进行冷冻，并在液氮中储存。复制品在Blazers BA 360冷冻蚀刻单元上制备，并在JEOL TEM 100C电子显微镜中以50,000倍放大倍数进行观察。