Comparative study of three methods for non-radioactive in vivo DNA labeling in Escherichia coli using nucleoside analogs.

In the present work, a comparative study of 5-FdUrd, thy-, and metabolic in vivo labeling methods for plasmid and chromosomal DNA in E. coli DH5alpha cells was performed in order to achieve the best thymidine substitution method by 5-BrdUrd. According to the colorimetric immunoenzymatic results, we found that the minimal detectable labeled DNA (MDLD) was 312pg with the 5-FdUrd and thy- methods for 5-BrdUrd labeled plasmid DNA.