S.K Rangari, M. K Rangari Fluorescence, primer, molecualr biology, research 60-62 Volume 1 (5) September, 2025 Fluorescence-labeled primers are short DNA sequences (primers) with a fluorescent dye attached, used for real-time monitoring and detection of nucleic acid amplification like in PCR. The fluorescence signal changes as the primer is incorporated into new DNA strands, with the signal increasing with more double-stranded DNA produced, which can be detected by a fluorescence-based amplification system. During PCR, the fluorescently labeled primer is incorporated into the newly synthesized DNA strand. Fluorescent primers are used in PCR to detect and quantify DNA amplification in real-time by emitting a fluorescent signal. This signal increases as more double-stranded DNA is produced, allowing for the detection of the target sequence and quantification of its amount without needing a separate post-PCR analysis.