Now that our SalivaDirect FDA EUA application for #SARS_CoV_2 diagnostics has been submitted, here is a sneak-peak at our validation results. medRxiv pre-print is forthcoming, but twitter is faster 😉
Overview: saliva w/o special tubes > no RNA extraction > dualplex PCR
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Overview: saliva w/o special tubes > no RNA extraction > dualplex PCR
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About SalivaDirect ➡️ covidtrackerct.com/about-salivadi…
Papers & Protocols ➡️ covidtrackerct.com/saliva-related…
SalivaDirect Results ➡️ covidtrackerct.com/salivadirect-r…
NBA validation study "Swish" ➡️ covidtrackerct.com/swish/
About SalivaDirect ➡️ covidtrackerct.com/about-salivadi…
Papers & Protocols ➡️ covidtrackerct.com/saliva-related…
SalivaDirect Results ➡️ covidtrackerct.com/salivadirect-r…
NBA validation study "Swish" ➡️ covidtrackerct.com/swish/
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We validated SalivaDirect with multiple reagents & platforms to:
-make it available to more labs
-avoid specific supply chain bottlenecks
-keep costs down.
We'll provide specific information on how to conduct bridging studies to validate additional reagents/equipement
We validated SalivaDirect with multiple reagents & platforms to:
-make it available to more labs
-avoid specific supply chain bottlenecks
-keep costs down.
We'll provide specific information on how to conduct bridging studies to validate additional reagents/equipement
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We conducted a lower limit of detection study with all of the reagent/equipment combinations using Non-COVID-19 saliva spiked with dilutions COVID-19 saliva.
The LOD = 6-12 virus copies/uL of saliva, depending on the combination.
We conducted a lower limit of detection study with all of the reagent/equipment combinations using Non-COVID-19 saliva spiked with dilutions COVID-19 saliva.
The LOD = 6-12 virus copies/uL of saliva, depending on the combination.
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Do we need expensive collection tubes to preserve #SARS_CoV_2 RNA in saliva? NO!!
@awyllie13 is about to drop some really nice data on this soon, but here are our prelim results. After 7 days at room temp (RT) or in a 30C incubator, #SARS_CoV_2 RNA detection increases!! 💪
Do we need expensive collection tubes to preserve #SARS_CoV_2 RNA in saliva? NO!!
@awyllie13 is about to drop some really nice data on this soon, but here are our prelim results. After 7 days at room temp (RT) or in a 30C incubator, #SARS_CoV_2 RNA detection increases!! 💪
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We also tested SalivaDirect on 52 saliva specimens collected from adults during the 2018/2019 and 2019/2020 (pre-COVID19) autumn/winter influenza seasons, and see *no cross-reactivity*. This is expected based on @VogelsChantal's Nat Med paper:
➡️ nature.com/articles/s4156…
We also tested SalivaDirect on 52 saliva specimens collected from adults during the 2018/2019 and 2019/2020 (pre-COVID19) autumn/winter influenza seasons, and see *no cross-reactivity*. This is expected based on @VogelsChantal's Nat Med paper:
➡️ nature.com/articles/s4156…
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The real test was clinical validation vs. NP swabs using the EUA approved TaqPath Assay (includes RNA extraction) using patient matched samples.
We found a 94% positive agreement between saliva tested via SalivaDirect and NP swabs via TaqPath.
The real test was clinical validation vs. NP swabs using the EUA approved TaqPath Assay (includes RNA extraction) using patient matched samples.
We found a 94% positive agreement between saliva tested via SalivaDirect and NP swabs via TaqPath.
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Looking at the CT values from our clinical sample type and platform comparisons, we find that patient-matched NP swabs and saliva tested on the TaqPath platform produce similar CT values. So saliva is good (but we knew that 😉)
Looking at the CT values from our clinical sample type and platform comparisons, we find that patient-matched NP swabs and saliva tested on the TaqPath platform produce similar CT values. So saliva is good (but we knew that 😉)
9/n
We found decreased detection (increased CT values) when testing saliva + SalivaDirect compared to NP swabs + TaqPath or saliva + TaqPath. This is becuase removing RNA extraction does decrease analytical sensitivity, but only by 1-3 CTs.
We found decreased detection (increased CT values) when testing saliva + SalivaDirect compared to NP swabs + TaqPath or saliva + TaqPath. This is becuase removing RNA extraction does decrease analytical sensitivity, but only by 1-3 CTs.
10/10
What's coming next? Data on pooling, detection of asymptomatic/presymtomatic cases, and practical considerations for scalability. We've come a long way, but still lots to do.
What's coming next? Data on pooling, detection of asymptomatic/presymtomatic cases, and practical considerations for scalability. We've come a long way, but still lots to do.
