Here’s the wet result of qNinja optical sensors using fluorescein sodium solution that simulates COVID-19 sample. Shortly speaking, we can expect that even a single copy of target DNA per tube can be detected well enough. Actual amplification with DNA will be held by ourselves and 3rd-party soon.
1. In some papers, COVID-19 swab sample contains 7*10^3 – 1*10^5 copy/uL as average (links will be added as comments below).
2. Put 0.01g fluorescein sodium (molecular weight 376.2699) in 100mL water = 0.26nM/uL = 1.6 * 10^14 copy/uL ≒ 2^24 * 1*10^5 copy/uL, equivalent to the 24th cycles of COVID-19 sample
3. Dilute 15 times to get 22uL 9th – 24th cycles samples.
qNinja could detect fluorescein clearly at 16-17th. Within 40th, typical limit of PCR cycles, it can detect 1*10^5 / 2^(40-17) copy/uL * 22uL/tube = 0.26 < 1 copy/tube.
Of course fluorescein sodium solution is not equal to the PCR product. We already got PCR Buffer, SYBR green and DNA sample (part of human FVIII exon 14) from 3rd party company. That will be used for actual tests.