Woldehiwet Z, Carter S D, Dare C
University of Liverpool, Department of Veterinary Pathology, Neston, Wirral, U.K.
J Comp Pathol. 1991 Nov;105(4):431-8. doi: 10.1016/s0021-9975(08)80112-0.
Cytoecetes phagocytophila, the causative agent of tick-borne fever, was successfully separated by Percoll and Renografin density gradient centrifugation and by cellular affinity chromatography, from the peripheral blood leucocytes of experimentally infected sheep. After centrifugation on Renografin or Percoll density gradients, infectious particles of C. phagocytophila banded at buoyant densities which ranged between 1.063 to 1.140. Rickettsiae separated by wheat germ lectin cellular affinity chromatography retained their morphology but often lost their infectivity. Cell-free C. phagocytophila remained infective to susceptible sheep for 6 months when kept at -114 degrees C in sucrose phosphate buffer with 10 per cent dimethylsulphoxide as a cryopreservative.
嗜吞噬细胞胞内埃立克体是蜱传热的病原体，通过Percoll和泛影葡胺密度梯度离心法以及细胞亲和色谱法，成功地从实验感染绵羊的外周血白细胞中分离出来。在泛影葡胺或Percoll密度梯度上离心后，嗜吞噬细胞胞内埃立克体的感染性颗粒在浮力密度为1.063至1.140之间形成条带。通过麦胚凝集素细胞亲和色谱法分离的立克次体保留了其形态，但常常失去其感染性。无细胞的嗜吞噬细胞胞内埃立克体在含有10%二甲亚砜作为冷冻保护剂的蔗糖磷酸盐缓冲液中于-114℃保存时，对易感绵羊仍具有6个月的感染性。
