Slot J W, Geuze H J
J Cell Biol. 1981 Aug;90(2):533-6. doi: 10.1083/jcb.90.2.533.
Gold particles in colloidal solutions often vary considerably in size. The finest sols (diameter less than 15 nm), especially, are very heterogeneous, as is indicated by coefficients of variance (CV) of 25-35%. We have complexed staphylococcal protein A with gold particles (PA/Au) and then fractionated the preparations by glycerol or sucrose gradient centrifugation into very homogeneous subfractions. In this way, PA/Au probes of almost any size between 4.5 and 15 nm could be prepared. The variation of the gold particles in these fractions resulted in CV's between 9 and 16%. The reactivity of the PA/Au complex was not affected by the gradient procedure, as was shown by single- and double-labeling immunocytochemistry of ultrathin cryosections of rat pancreatic tissue.
胶体溶液中的金颗粒大小常常差异很大。尤其是最细的溶胶（直径小于15纳米）非常不均一，变异系数（CV）为25%至35%就表明了这一点。我们已将葡萄球菌蛋白A与金颗粒复合（PA/Au），然后通过甘油或蔗糖梯度离心将制剂分离成非常均一的亚组分。通过这种方式，可以制备出大小在4.5至15纳米之间几乎任何尺寸的PA/Au探针。这些组分中金颗粒的变异导致CV在9%至16%之间。如对大鼠胰腺组织超薄冰冻切片进行的单标记和双标记免疫细胞化学所示，PA/Au复合物的反应性不受梯度离心过程的影响。
