CIL:754, Patiria miniata, sperm. In Cell Image Library

Phosphorus has a characteristic electron energy loss with an edge at 160 eV. The Zeiss 902 electron microscope permits images to be recorded at different energy losses which can be digitized and processed to yield a net phosphorus image. For nuclear chromatin, phosphorus is primarily located in DNA, allowing its distribution in chromatin fibers to be mapped. Electron energy loss (EELS) imaging is also known as electron spectroscopic imaging (ESI) and electron energy filtering TEM (EFTEM). Starfish sperm chromatin, which has clearly defined chromatin fibers was fixed, embedded in Lowicryl at low temperature, thin sections prepared and imaged unstained. The 3 grouped images were recorded with a Zeiss 902 energy filtered TEM at 80KV using 5eV windows centered on energy loss values of 160 (this image), 120, and 104eV.

磷具有特征性的电子能量损失谱，其吸收边位于160 eV处。蔡司902型电子显微镜可在不同能量损失条件下采集图像，经数字化处理后可得到净磷分布图像。对于细胞核染色质而言，磷主要分布于DNA分子中，因此可对其在染色质纤维内的分布进行定位成像。电子能量损失谱成像（Electron Energy Loss Spectroscopy, EELS）又被称为电子光谱成像（Electron Spectroscopic Imaging, ESI）与电子能量过滤透射电子显微镜成像（Electron Energy-Filtering TEM, EFTEM）。海星精子染色质具有清晰可辨的染色质纤维，经固定、低温包埋于Lowicryl树脂中、制备超薄切片后，进行未染色成像。本次采集的3组图像均采用蔡司902型能量过滤透射电子显微镜，在80 kV加速电压下拍摄，所用的5 eV能量窗口分别以160 eV（即本图像）、120 eV与104 eV的能量损失值为中心。