Abuelo J G, Moore D E
J Cell Biol. 1969 Apr;41(1):73-90. doi: 10.1083/jcb.41.1.73.
Human lymphocytes were grown in short-term tissue culture and were arrested in metaphase with Colcemid. Their chromosomes were prepared by the Langmuir trough-critical point drying technique and were examined under the electron microscope. In addition, some chromosomes were digested with trypsin, Pronase, or DNase. The chromosomes consist entirely of tightly packed, 240 +/- 50-A chromatin fibers. Trypsin and Pronase treatments induce relaxation of fiber packing and reveal certain underlying fiber arrangements. Furthermore, trypsin treatment demonstrates that the chromatin fiber has a 25-50 A trypsin-resistant core surrounded by a trypsin-sensitive sheath. DNase digestion suggests that this core contains DNA.
人类淋巴细胞在短期组织培养中生长,并用秋水仙酰胺使其停滞在中期。它们的染色体通过朗缪尔槽 - 临界点干燥技术制备,并在电子显微镜下检查。此外,一些染色体用胰蛋白酶、链霉蛋白酶或脱氧核糖核酸酶进行消化。染色体完全由紧密堆积的、240±50埃的染色质纤维组成。胰蛋白酶和链霉蛋白酶处理可诱导纤维堆积松弛,并揭示某些潜在的纤维排列。此外,胰蛋白酶处理表明染色质纤维有一个25 - 50埃的抗胰蛋白酶核心,周围是一个对胰蛋白酶敏感的鞘。脱氧核糖核酸酶消化表明这个核心含有DNA。