LOW COST CCD CAMERAS FOR PHILIPS CM10 ELECTRON MICROSCOPE

适用于飞利浦 CM10 电子显微镜的低成本 CCD 相机

• 批准号: 6278680
• 负责人: DAVID N MASTRONARDE
• 金额: $ 1.24万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-12-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6278680
• 关键词: animal tissue; biomedical resource; computers; growth /development; human tissue; microorganism; microscopy; model design /development; technology /technique

Our grant has funds, to be matched by departmental funds, to obtain a CCD camera system for our department's Philips TEM. The main purpose of this system is to allow direct digitization of images suitable for reconstructions from serial sections. Currently this work is done by taking pictures on film and digitizing with a video camera. The characteristics of images acquired in this way provide a benchmark for the performance of a CCD camera system. We arranged for tests to be performed on three cameras: the Gatan Bioscan 792, AMT's 1K by 1K camera, and a 1. by 1. camera from Princeton Instruments. Each manufacturer provided us with digital images of the edge of a slot grid, axonemes from Chlamydomonas in cross and longitudinal section (pixel size about 1 nm), and Golgi regions from NRK cells (pixel size about 2.5 nm). The image of an edge could be analyzed to determine the Modulation Transfer Function (MTF) of the camera system, using software developed in our laboratory for measuring MTF from such images. The other images could be compared with numerous similar images photographed on film and digitized with a video camera. Both Princeton Instruments and AMT cameras are lens-coupled and had a spatial resolution only half as good as when digitizing from film, which means that the effective number of pixels is only 500-600, not 1000-1200. The Gatan camera is fiber-optic coupled and has adequate resolution, but in these initial tests the phosphor was too sensitive and the camera saturated at relatively low electron doses. Thus it was impossible to obtain an image with an acceptable signal-to-noise ratio. Both AMT and Gatan have made improvements since these tests. AMT has developed a higher-resolution lens. We have evaluated images from the CCD camera with this lens and found that the overall resolution is better by about 35%, so that the effective number of pixels is now 730. Gatan has reduced the phosphor sensitivity in the Bioscan camera and the images acquired with it now appear to have a reasonable signal-to-noise ratio.

我们的赠款有资金，将与部门资金相匹配，以 为我们部门的飞利浦 TEM 获取 CCD 摄像系统。 主要 该系统的目的是允许图像直接数字化 适合从连续切片重建。 目前这个 工作是通过在胶片上拍照并用视频数字化来完成的 相机。 以这种方式获取的图像的特征提供了 CCD相机系统性能的基准。 我们安排在三台相机上进行测试：Gatan Bioscan 792，AMT 的 1K x 1K 相机，以及 1. x 1. 相机 普林斯顿仪器公司。 每个制造商都为我们提供了数字 槽网格边缘的图像，来自衣藻的轴丝 横截面和纵切面（像素大小约 1 nm）和高尔基体 来自 NRK 细胞的区域（像素大小约为 2.5 nm）。 的图像 可以分析边缘以确定调制传递函数 （MTF）相机系统，使用我们实验室开发的软件 用于从此类图像测量 MTF。 其他图像可能是 与胶片上拍摄的许多类似图像进行比较 用摄像机数字化。 Princeton Instruments 和 AMT 相机都是镜头耦合的，并且具有 空间分辨率只有胶片数字化时的一半， 这意味着有效像素数只有500-600，而不是 1000-1200。 Gatan 相机采用光纤耦合，具有足够的 分辨率，但在这些初始测试中荧光粉太敏感 并且相机在相对较低的电子剂量下饱和。 因此它 不可能获得具有可接受信噪比的图像 比率。 自这些测试以来，AMT 和 Gatan 都取得了改进。 AMT 有 开发出更高分辨率的镜头。 我们评估了来自 使用该镜头的CCD相机，发现整体分辨率为 提高了约 35%，因此现在的有效像素数为 730. Gatan 降低了 Bioscan 相机中的磷光体灵敏度 现在用它获得的图像似乎具有合理的 信噪比。