Protocol for fluorescence in situ hybridization of a repetitive DNA probe to human chromosomes in suspension. Hybridization technique which does not need formamide and dextran sulfate. As a model system, we used the repetitive
specific human DNA probe pUC 1.77, labeled it with digoxigenin-11-dUTP by nick-translation, and hybridized it to
metaphase chromosomes in suspension. These chromosomes were isolated by standard techniques from human lymphocytes. - [Read Fluorescence In Situ Hybridization of a Repetitive DNA Probe to Human Chromosomes in Suspension]
DEAE-dextran is generally used to obtain a burst of transient expression of cloned genes after transfection of mammalian cells. Many variants of the technique have been described, all of which seek to maximize the uptake of DNA and to minimize the cytotoxic effects of DEAE-dextran. In this protocol cells are exposed briefly to a high concentration of DEAE-dextran-DNA and then to chloroquine diphosphate, which is a facilitator of transfection. - [Read Transfection Mediated by DEAE-Dextran: High-efficiency Method Protocol]