CIL:14702, Oscillatoria tenuis. In Cell Image Library

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. Cells might be damaged in this particular sample.

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 33,000X magnification.

细颤藻（Oscillatoria tenuis）作为丝状蓝细菌，其营养细胞的类囊体具备放氧光合作用的能力。对该营养细胞的冷冻断裂复型（freeze-fracture replicas）样品可揭示类囊体的结构。
冷冻断裂过程会沿膜的疏水内部区域将膜劈开，从而暴露出两个互补的断裂面。该批次样品中的部分细胞可能已受损。
细颤藻培养物在琼脂平板上进行维持培养。收集细胞并将其重悬于10 mL双蒸水（dH2O）中，使用临床离心机以2000 g的离心力离心10分钟，随后将沉淀重悬于5 mL双蒸水中；在持续搅拌的条件下，于1小时内缓慢加入5 mL 70%甘油，再次以2000 g离心10分钟。将所得沉淀置于铜支撑载网上，采用氟利昂12（Freon 12）进行液氮冷冻，并置于液氮中保存。复型样品在Blazers BA 360型冷冻蚀刻仪（Blazers BA 360 freeze-etch unit）上制备，并在JEOL TEM 100C型透射电子显微镜下以33000倍放大倍数进行观测。