Nucleic acid probe design and its melting profile.

<p>(A) Probe consists of a target-hybridising oligonucleotide (THO) labeled with a <u>F</u>luorophore at the 5′ end and a <u>Q</u>uencher at the 3′end, and a partially complementary oligonucleotide (PCO) without a label. The hybrid of THO:PCO is named plus probe. The melting curve shows decreased fluorescence emission when temperature rises (left panel); the negative derivative plot of the emission reading versus temperature reveals a positive value of the melting peak (right panel). (B) Minus probe consists of a THO labeled with a <u>F</u>luorophore at the 5′ end and a <u>Q</u>uencher at the 3′end, and a PCO labeled with a <u>Q</u>uencher at the 3′ end. The melting curve shows increased fluorescence emission when temperature rises (left panel); the negative derivative plot of the emission reading versus temperature reveals a negative value of the melting peak (right panel).