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What is the probe?
- Aug 15, 2018 -

The probe is the contact medium for electrical testing and is a high-end precision electronic hardware component.


Biological aspect

The probe is a small piece of single-stranded DNA or RNA fragment (approximately 20 to 500 bp) used to detect a nucleic acid sequence complementary thereto. The double-stranded DNA is heat-denatured into a single strand and subsequently labeled as a probe with a radioisotope (usually with phosphorus-32), a fluorescent dye or an enzyme such as horseradish peroxidase. Phosphorus-32 is typically incorporated into the phosphate group of one of the four nucleotides that make up the DNA, while the fluorescent dye and enzyme are covalently linked to the nucleic acid sequence.


When the probe is hybridized to the sample, the probe and the nucleic acid (DNA or RNA) sequence complementary thereto are closely linked by hydrogen bonding, and then the excess probe that has not been hybridized is washed away. Finally, depending on the type of the label of the probe, autoradiography, fluorescence luminescence, enzyme-linked chemiluminescence, or the like can be performed to determine whether or not the sample contains the sequence to be tested (ie, a sequence complementary to the probe).