Fluorescent In Situ Hybridization technique (FISH) is based on the hybridization of fluorescent labeled oligonucleotide probe to a specific complementary DNA or RNA sequence in whole and intact cells.1 Microbial FISH allows the visualization, identification and isolation of bacteria due to recognition of ribosomal RNA also in unculturable samples.2
FISH technique can serve as a powerful tool in the microbiome research field by allowing the observation of native microbial populations in diverse microbiome environments, such as samples from human origin (blood3 and tissue4), microbial ecology (solid biofilms5 and aquatic systems6) and plants7.
Prokaryotic single cell life forms are divided into two domains, called Bacteria and Archaea, originally categorized as Eubacteria and Archaebacteria.8 However both terms, Eubacteria and Bacteria are still being used in microbiology.
The Negative control non-specific, nonsense probe, is used in the FISH experiments to detect nonspecific binding of the probes and set the appropriate conditions for the experiment.9
The negative control probe was used in FISH technique on various samples such as, pure culture (as described in the figure legends) and blood cultures9,10.
It is strongly recommended to include positive and negative controls in FISH assays to ensure specific binding of the probe of interest and appropriate protocol conditions. We offer positive (MBD0032/33) and negative (MBD0034/35) control probes, that accompany the specific probe of interest.