Catalyzed reporter deposition Fluorescence In Situ Hybridization
(CARD-FISH) is a powerful methodology with a growing number of
applications in the quantitative evaluation of microbial
populations of complex ecosystems. CARD-FISH is an improvement
over traditional FISH especially suitable for aquatic habitats
with small, slow growing, or starving bacteria, in which the
signal intensities of hybridized cells is frequently below
detection limits or lost in high fluorescence background of
dense mineral matrixes. CARD is based on the tyramide signal
amplification. It was introduced more than one decade ago for
immunoblotting and immunosorbent assays using horseradish
peroxidase (HPR) and haptenized tyramines. The basis and
methodology for this technique is described in Pernthaler et al.
(2002). CARD-FISH and bioleaching CARD-FISH is an important
improvement on the fluorescence in situ hybridization technique,
very useful for the detection, identification and quantification
of microorganisms involved in bioleachin