A constellation of chromosome conformation capture methods (С-methods) are an important tool for biochemical analysis of the spatial interactions between DNA regions that are separated in the primary sequence. All these methods are based on the long sequence of basic steps of treating cells, nuclei, chromatin, and finally DNA, thus representing a significant technical challenge. Here, we present an in-depth study of the basic steps in the chromatin conformation capture procedure (3С), which was performed using Drosophila Schneider 2 cells as a model. We investigated the steps of cell lysis, nuclei washing, nucleoplasm extraction, chromatin treatment with SDS/Triton X-100, restriction enzyme digestion, chromatin ligation, reversion of cross-links, DNA extraction, treatment of a 3C library with RNases, and purification of the 3C library. Several options were studied, and optimal conditions were found. Our work contributes to the understanding of the 3C basic steps and provides a useful guide to the 3C procedure.

一组染色体构象捕获方法（С-方法）是对初级序列中分离的 DNA 区域之间的空间相互作用进行生化分析的重要工具。所有这些方法都基于处理细胞、细胞核、染色质和最终 DNA 的一系列基本步骤，因此是一项重大的技术挑战。在这里，我们对染色质构象捕获程序 (3С) 的基本步骤进行了深入研究，该程序使用 Drosophila Schneider 2 细胞作为模型进行。我们研究了细胞裂解、细胞核洗涤、核质提取、用 SDS/Triton X-100 处理染色质、限制酶消化、染色质连接、交联逆转、DNA 提取、用 RNases 处理 3C 文库和纯化的步骤3C图书馆。研究了几个选项，并找到了最佳条件。我们的工作有助于理解 3C 基本步骤，并为 3C 程序提供有用的指南。