Evaluation of a fluorescence in situ hybridization (FISH)-based method for detection of SARS-CoV-2 in saliva

Abstract

The use of a non-invasive fluorescence in situ hybridization (FISH)-based method on saliva for the detection of SARS-CoV-2 is evaluated in a proof-of-concept study and thereafter utilized in an outpatient setting with the Biotrack-MED® analyzer. For a proof-of-concept study, saliva samples were obtained from 28 persons with mild or moderate COVID-19-related symptoms who were tested RT-PCR positive or negative for SARS-CoV-2. In an outpatient setting, 972 individual saliva samples were utilized. All saliva samples were FISHed with a Cy3-labeled SARS-CoV-2-specific DNA probe and were analyzed manually by fluorescence microscopy (proof-of-concept) or with the SARS-CoV-2 application of the Biotrack-MED® analyzer, a semi-autonomous multi-sample filter cytometer. The proof-of-concept study showed a sensitivity of 96.0% and a specificity of 98.5% and is therefore comparable to the RT-PCR analysis of nasopharyngeal swabs. The outpatient setting showed a sensitivity of 90.9% and a specificity of 94.5% and seems therefore a valid assay for the detection of SARS-CoV-2 in individuals that are healthy, mild or moderate symptomatic. In conclusion, the method evaluated in this study, the FISH-based SARS-CoV-2 application of the Biotrack-MED® analyzer, is a sensitive and reliable assay for the detection of SARS-CoV-2 in the general population.

Role of aptamer technology in extracellular vesicle biology and therapeutic applications

“…For example, the LOD for SARS-CoV-2 detection using an electrochemical aptasensor is <1100 copies per mL, 149 while for a capacitive laser-induced graphene-based aptasensor, it stands at 1790 copies per mL. 150 These LODs translate to a detection capability that is 2 orders of magnitude beyond the acceptable diagnostic sensitivity for SARS-Cov-2 (1.0 × 10 6 genome copies per mL) according to the World Health Organization. 151 As for protein detection, an on-chip integrated graphene aptasensor achieves an LOD of 160 aM for COVID-19 neutralizing antibodies in serum, 152 which is 5 orders of magnitude lower than the minimum target concentration (30 pM) in patients.…”

A Molecular Approach for Detecting Bacteria and Fungi in Healthcare Environment Aerosols: A Systematic Review

“…FISH involves the use of fluorescently labeled nucleic acid probes to specifically bind to target DNA or RNA sequences in microbial cells. It is a direct detection method that can be applied to assess the abundance and spatial distribution of specific microorganisms in aerosol samples [18,25]. Furthermore, DNA hybridization involves the hybridization of DNA probes with complementary sequences in the target microorganisms.…”