Clara Franzini-Armstrong (2011) CIL:37398, damselfly, flight muscle cell. CIL. Dataset

The image shows the surface of the ribbon-like myofibrils, with some remnants of the SR attached mostly at the Z lines. The regular disposition of attached cross bridges is visible in many areas. Most images show fractures through the outer membrane of mitochondria and SR/T tubules of dyads nestled in long grooves of the mitochondrial surface. All leaflets of the membranes appear in the images. This image is part of the group image CFA00513 (file cfa1061.mrc to cfa1097.mrc). Negatvies scanned at LBL then reduced in size for upload TEM magnifications not currently available. Scan step size is 6.3 micron, then reduced in size 4X for upload, for an effective pixel size of 25 micron.

Technical details:
Heads and tail were removed, the thorax was bisected and immersed in 100 mM KCl, 10 mM EDTA, 10 Triton X for a few hrs, to depolarize and skin the fibers, then maintained at -20 C in 50% glycerol in the same solution for several weeks to induce rigor by eliminating ATP. The muscle was gently homogenized in a waring blender in 0.9% NaCl. The fibrils were deposited on glass and sequentially fixed in 0.1% glutaradehyde in 0.1 M cacodylate buffer, rinsed in 100 mM ammonium acetate, treated with 1% uranyl acetate for 30 seconds, rinsed in 40% methanol and frozen in liquid nitrogen. The fibrils were freeze dried at -90 C for 30 minutes and rotary shadowed with platinum either at 25C or 45C in a Balzer’s 400 freeze fracture. The glass was dissolved in hydrofluric acid and the replicas were mounted on copper grids and examined in a Philips 410 Microscope.

References for the image:
Loesser, K.E. and Franzini-Armstrong, C. A simple method for freeze-drying of macromolecules and macromolecular complexes. J. Struct. Biol. 103: 48-56, 1990. Bard, F., Franzini-Armstrong, C. and Ip W. Rigor cross bridges are double headed in fast muscle from crayfish. J. Cell Biol. 105: 2225-2234, 1987.

本图像展现了类似带状肌原纤维的表面，其中部分肌浆网残留物主要附着于Z线附近。在多个区域中，附着交叉桥的规则排列清晰可见。大多数图像展示了穿过线粒体外膜及位于线粒体表面长沟中的二联肌纤维的SR/T管腔的断裂。所有膜瓣均在图像中呈现。该图像属于图像组CFA00513（文件cfa1061.mrc至cfa1097.mrc）。底片在LBL扫描后缩小尺寸以供上传，透射电子显微镜（TEM）放大倍数目前不可用。扫描步长为6.3微米，上传前缩小4倍，有效像素大小为25微米。

技术细节：去除了头部和尾部，将胸部横切并浸泡于100 mM氯化钾、10 mM乙二胺四乙酸、10毫升的Triton X中数小时，以去极化和剥皮纤维，然后置于-20°C的50%甘油和相同溶液中数周，通过消除ATP来诱导僵直。肌肉在0.9%氯化钠中用Waring搅拌器轻轻匀质化。肌原纤维沉积在玻璃上，并依次用0.1%戊二醛在0.1 M草酸盐缓冲液中固定，用100 mM乙酸铵溶液冲洗，用1%铀酸乙酸处理30秒，用40%甲醇冲洗，并在液氮中冷冻。肌原纤维在-90°C下冻干30分钟，并在25°C或45°C的Balzer 400冷冻断裂装置中使用铂进行旋转阴影。玻璃在氢氟酸中溶解，复制品安装在铜网上，并在Philips 410显微镜下进行观察。

图像参考：Loesser, K.E. 和 Franzini-Armstrong, C. 简化的大分子和大分子复合物冷冻干燥方法。J. Struct. Biol. 103: 48-56, 1990。Bard, F., Franzini-Armstrong, C. 和 Ip W. 青虾快速肌肉中的僵直交叉桥为双头。J. Cell Biol. 105: 2225-2234, 1987。