Real-time quaking-induced conversion

Real-time quaking-induced conversion (RT-QuIC) is a highly sensitive diagnostic method used to detect prion diseases. This technique is based on the ability of an abnormal prion protein to convert a normal prion protein into an abnormal form.

Overview

RT-QuIC is a novel assay that allows for the detection of minute amounts of prion proteins in biological samples. The technique is based on the principle of prion protein conversion, where a normal prion protein (PrP^C) is converted into an abnormal, disease-associated form (PrP^Sc).

Procedure

The RT-QuIC procedure involves the incubation of a test sample with a recombinant prion protein substrate. This is followed by periodic shaking (or "quaking") of the sample. The shaking induces the conversion of the normal prion protein into the abnormal form. The conversion process is monitored in real-time using a fluorescent dye that binds to the newly formed abnormal prion proteins. The fluorescence intensity is measured over time, and an increase in fluorescence indicates the presence of abnormal prion proteins in the sample.

Applications

RT-QuIC has been used to detect prion diseases in various biological samples, including cerebrospinal fluid, nasal brushings, and skin. It has also been used to detect prion diseases in various species, including humans, cattle, and sheep.

Advantages and Limitations

The main advantage of RT-QuIC is its high sensitivity and specificity for prion diseases. It can detect prion proteins at concentrations as low as a few femtograms per milliliter. However, the technique requires specialized equipment and trained personnel, which may limit its use in some settings.

See Also

• Prion
• Prion diseases
• Protein misfolding
• Neurodegenerative diseases