Pnafishan Intelligent Stain

PNA-FISH is a novel technique that combines the simplicity of current staining methods such as Gram staining with the specificity of molecular techniques (Fig. 1).[9] In this way, presumptive detection of the causative agent routinely performed by microscopical examination can be improved to provide final identification. Importantly, PNA-FISH is performed directly on smears fixed onto microscope slides by standard methods, such as flame fixation, methanol fixation, or heat fixation, without any other pretreatment or permeabilization steps known from DNA-based tests.

PNA-FISH uses rRNA as target not only because of its phylogenetic superiority as described above, but also because each microorganism harbors several thousand rRNA molecules. This abundance of rRNA target molecules allows individual cells to be detected and identified directly by fluorescent-labeled probes, also called ''phylogenetic stains''[10]—attributes that make the PNA-FISH technology extremely simple and user-friendly compared with polymerase chain reaction (PCR) and other molecular technologies.

Moreover, the PNA-FISH concept is directly compatible with a variety of sample types.[9] Blood cultures, as will be reviewed later, are one example where the complex medium contains well-known inhibitors and interference substances, such as sodium polyanetholesul-fonate, charcoal particle, or resins, for diagnostic procedures. Numerous attempts to perform blood culture identification directly from the positive blood culture bottles have been reported in the past, but with variable sensitivities and specificities, and have often only been evaluated on a single blood culture medium and rarely on highly complex media with charcoal or resins. In contrast, PNA-FISH is compatible with all major blood culture media[11]—a key feature that is ascribed to the inert and synthetic PNA probe molecule.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

Get My Free Ebook

Post a comment