Chapter 8 Application of Precursors Adsorbed on Activated Charcoal for Labeling of Mammalian DNA in Vivo

Abstract

Publisher Summary This chapter discusses a technique of adsorbed precursors that can be successfully used for continuous labeling of mammalian DNA. When applied as a “depot,” a constant concentration of the precursor is maintained in the organism for 4-5 days. In several cases the described technique of adsorbed precursors has demonstrated its ability to meet problems hardly to be solved in any other way. For heavy substitution of DNA in vivo it is unique, and in no other way could such a high degree of incorporation of exogenous precursor be obtained. However, it has several disadvantages, the most disturbing of which is the nature of charcoal itself. In the case of continuous labeling, when 0.1–0.3 mg/gm body weight of activated charcoal is administered intraperitoneally, the animals are practically not affected. However, in “heavy substitution” experiments, when a rather great amount of charcoal (2–3 mg/g body weight) is introduced intraperitoneally, they suffered acute sterile peritonitis, and some died 3-5 days after the treatment. The charcoal suspension is injected subcutaneously, but unfortunately, in this case the incorporation of the precursor into DNA is 20–50 times less effective. If a different adsorbent could be found, which is less irritating than charcoal and could be degraded and metabolized in mammalian organism, the application of the method would be considerably extended.