Repetitive DNA sequences are abundant in the genome of most biological species. These sequences are naturally "preamplified", which makes them a preferential target for a variety of biological assays. Current methods to detect specific DNA sequences are based on the quantitative polymerase chain reaction (PCR), which relies on target amplification by Taq polymerase and uses a fluorescent resonance energy transfer (FRET)-based probe. Here, to rapidly detect a repetitive DNA sequence, we combine a highly sensitive magnetic modulation biosensing (MMB) system and a modified double-quenched FRET-based probe. The high numbers of copies of the female-specific XhoI sequence of the domestic chicken (Gallus gallus), combined with the low background fluorescence levels of the modified double-quenched probe and the high sensitivity of the MMB system, allow us to determine the chick sex in ovo within 13 min, with 100% sensitivity and specificity. Compared to quantitative PCR, the presented assay is 4-9 times faster. More broadly, by specifically tailoring the primers and probe, the proposed assay can detect any target DNA sequence, either repetitive or nonrepetitive.
|Number of pages||7|
|State||Published - 31 Jul 2019|
Bibliographical noteFunding Information:
The authors thank Shira Roth and Yehudit Michelson for their valuable discussions, and Meir Cohen for technical assistance. This research was supported by the Israel Science Foundation (Grant No. 1142/15) and the Israel Innovation Authority (Kamin, Grant No. 59042). James Ballard provided an editorial review of the manuscript.
Copyright © 2019 American Chemical Society.