  DNA and RNA quadruplexes are extensively studied for the key roles they are
suspected to play in the cellular regulation networks at both genomic and
transcriptomic levels. The reliable detection of quadruplexes in cells was and
remains a challenging task. Here, we describe the various strategies that have
been implemented over the past years to visualize functionally relevant DNA and
RNA quadruplexes in human cells, from immunodetection studies to the design and
use of quadruplex-specific turn-on fluorescent probes.
