Andronico F, Beccari E
Biochim Biophys Acta. 1975 Jun 16;395(2):120-7. doi: 10.1016/0005-2787(75)90150-1.
A DNA fraction highly enriched in tRNA genes can be isolated from the Xenopus laevis genome by the use of Ag+/Cs2SO4 density gradients. Ag+ shows a low affinity for some tRNA cistrons, allowing their separation from bulk DNA upon equilibrium centrifugation in a Cs2SO4 density gradient. Contaminating DNA in the resulting tDNA fraction is further removed by two additional CsCl density gradient centrifugations. The final DNA fraction is 60-fold enriched in tRNA genes, compared to the starting DNA material.
通过使用银离子/硫酸铯密度梯度，可以从非洲爪蟾基因组中分离出高度富集tRNA基因的DNA组分。银离子对某些tRNA顺反子的亲和力较低，在硫酸铯密度梯度中进行平衡离心时，可使其与总DNA分离。通过另外两次氯化铯密度梯度离心进一步去除所得tDNA组分中的污染DNA。与起始DNA材料相比，最终的DNA组分中tRNA基因富集了60倍。
