Furthermore, dark quenchers enable multiplexing (when two or more reporter-quencher probes are used together). Dark quenchers are used in molecular biology in conjunction with fluorophores. Combining probe compounds and scavengers or quenchers increases accuracy. Dark quenchers are dyes with no native fluorescence. Molecular oxygen, iodide ions and acrylamide are common chemical quenchers. An alternative real-time multiplexing approach based on fluorescence quenchers has been reported. Quenchers are designed using the same principles as scrubbers.