What is the primary use of biotin and digoxigenin in laboratory settings?

The primary use of biotin and digoxigenin in laboratory settings is in probe labeling for the visualization of nucleic acids. Both biotin and digoxigenin are commonly used as haptens in various molecular biology techniques, particularly in the context of hybridization assays. By attaching these molecules to nucleic acid probes, researchers can detect specific sequences of DNA or RNA within a sample.

In methods such as Southern or Northern blotting, for instance, biotin-labeled or digoxigenin-labeled probes can hybridize with complementary sequences in the target nucleic acids. Following hybridization, the presence of these labeled probes can be visualized through various detection methods, such as enzyme-linked assays or fluorescence. This capability to label and subsequently detect specific nucleic acid sequences is crucial for applications in gene expression analysis, genetic research, and diagnostics.

While protein synthesis, cell culture maintenance, and DNA sequencing are important aspects of molecular biology, they do not utilize biotin and digoxigenin in the same manner as probe labeling does, making this answer the most accurate choice regarding their primary application in laboratory settings.