TABLE 1.
Samples tested by SARS-CoV-2 Ag-RDTs with and without manufacturer buffer
| Category | Branda | Description | Avg. pH (± SD)a | Panbio result |
Veritor result |
RT-PCR result | ||
|---|---|---|---|---|---|---|---|---|
| Sample, direct | Swab of sample in buffer | Sample, direct | Swab of sample in buffer | |||||
| Food products (n = 33) | Bragg | Apple cider vinegar | NA | INV | NEG | INV | NEG | NA |
| NA | Lemon, juice (fresh) | NA | INV | NEG | INV | NEG | NA | |
| NA | Lime, juice (fresh) | NA | INV | NEG | INV | NEG | NA | |
| Nakano | Rice vinegar | NA | INV | NEG | NEG | NEG | NA | |
| Natrel | Milk, lactose-free | NA | NEG | NEG | NEG | NEG | NA | |
| Scotsburn | 18% cream | NA | NEG | NEG | NEG | NEG | NA | |
| Scotsburn | Milk, 2% | NA | NEG | NEG | NEG | NEG | NA | |
| Farmer’s | Milk, 2% | NA | POSb | NEG | NEG | NEG | NA | |
| Farmer’s | Milk, 1% | NA | POSb | NEG | NEG | NEG | NA | |
| Farmer’s | Milk, fat-free skim | NA | POS | NEG | NEG | NEG | NA | |
| Bubbly | Soda | NA | POSb | NEG | NEG | NEG | NA | |
| Pepsi | Soda | NA | POSb | NEG | NEG | NEG | NA | |
| Coca-Cola | Soda | NA | POSb | NEG | NEG | NEG | NA | |
| Tim Horton’s | Apple juice, pure | NA | POSb | NEG | NEG | NEG | NA | |
| Tim Horton’s | Coffee, black | NA | POS | NEG | NEG | NEG | NA | |
| Simply | Apple juice, pure pressed | NA | POS | NEG | NEG | NEG | NA | |
| NA | Honeycrisp apple, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | Tangerine, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | Watermelon, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | Red grapes, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | Green grapes, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | Peach, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | Wild blueberries, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | Tomato, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| NA | English cucumber, juice (fresh) | NA | POS | NEG | NEG | NEG | NA | |
| Heinz | Relish | NA | POS | NEG | NEG | NEG | NA | |
| Heinz | Ketchup | NA | POS | NEG | NEG | NEG | NA | |
| Heinz | Mustard | NA | POS | NEG | NEG | NEG | NA | |
| Stellenbosch | Wine, cabernet | NA | POS | NEG | NEG | NEG | NA | |
| Bud Light | Beer | NA | POS | NEG | NEG | NEG | NA | |
| Fisherman’s Helper | Rum, white | NA | POS | NEG | NEG | NEG | NA | |
| Crown Royal | Maple finished whisky | NA | POS | NEG | NEG | NEG | NA | |
| Jameson | Irish whiskey | NA | POS | NEG | NEG | NEG | NA | |
| Water samples (n = 24) |
Sigma Life Sciences | Double processed, tissue culture water, sterile filtered | 4.00 (±0.01) | POS | NEG | NEG | NEG | NEG |
| Montellier | Carbonated spring water | 4.68 (±0.00) | POS | NEG | NEG | NEG | NEG | |
| Invitrogen | Ultrapure distilled water, DNase- and RNase-free | 4.80 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Aquafina | Demineralized water, reverse osmosis | 5.05 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| S. Pellegrino | Carbonated natural mineral water | 5.09 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Canadian Springs | Distilled water, ozonated | 5.31 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Dasani | Remineralized water, reverse osmosis treated | 5.68 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Big8 | Distilled water, ozonated | 6.25 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Big8 | Spring water, ozonated | 6.26 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Glaceau Smart | Vapor distilled water with added electrolytes | 6.71 (±0.02) | POS | NEG | NEG | NEG | NEG | |
| NA | Municipal water (Halifax, Nova Scotia, 12 May 2021) | 6.75 (±0.02) | POS | NEG | NEG | NEG | NEG | |
| Fiji | Natural spring water, tropical rain filtered through volcanic rock | 7.25 (±0.02) | POS | NEG | NEG | NEG | NEG | |
| Simple Drop | Natural spring water | 7.26 (±0.02) | POS | NEG | NEG | NEG | NEG | |
| Pathwater | Purified water, reverse osmosis treated, ozonated, and electrolytes added, pH balanced, pH 7.5+ | 7.27 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Art Life WTR | Purified water, mineralized and electrolytes added, pH balanced | 7.28 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Evian | Spring water, natural electrolytes, pH 7.2 | 7.39 (±0.02) | POS | NEG | NEG | NEG | NEG | |
| NA | Rainwater (Halifax, Nova Scotia, 12 May 2021) | 7.47 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Icelandic Glacial | Natural spring water | 7.58 (±0.02) | POS | NEG | NEG | NEG | NEG | |
| Nestle Pure Life | Natural spring water, ozonated | 7.75 (±0.02) | POS | NEG | NEG | NEG | NEG | |
| Earth Group | Spring water | 7.80 (±0.03) | POS | NEG | NEG | NEG | NEG | |
| Eska | Natural spring water, pH 7.4 | 7.81 (±0.00) | POS | NEG | NEG | NEG | NEG | |
| Smart Moodwater | Naturally alkaline spring water, pH 8+ | 7.91 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Flow | Naturally alkaline spring water, pH 8.1 | 8.02 (±0.00) | POS | NEG | NEG | NEG | NEG | |
| Glaceau Smart | Mineralized treated water, alkaline pH 9+ | 9.33 (±0.00) | POS | NEG | NEG | NEG | NEG | |
| Laboratory buffers and media (n = 14) |
Teligent | 0.9% saline | 5.62 (±0.02) | POS (weak) | NEG | NEG | NEG | NEG |
| Boston BioProducts | 0.5 M Pipes buffer, pH 6.8 | 6.66 (±0.01) | POSb | NEG | NEG | NEG | NEG | |
| Fisher Scientific | 10 mM Tris-HCl, 1 mM EDTA (TE) buffer, molecular grade, pH 7.4 | 7.14 (±0.01) | POS | NEG | NEG | NEG | NEG | |
| Sigma Life Sciences | Dulbecco’s phosphate buffered saline (PBS) | 7.18 (±0.01) | POSb | NEG | NEG | NEG | NEG | |
| LiofilChem | Viral transport media (VTM) | 7.24 (±0.01) | POSb | NEG | NEG | NEG | NEG | |
| Redoxica | Viral transport media (VTM) with fetal bovine serum (FBS) | 7.33 (±0.01) | POSb | NEG | NEG | NEG | NEG | |
| Becton Dickinson | Veritor sample buffer | 7.33 (±0.00) | NEG | NEG | NEG | NEG | NEG | |
| Copan Diagnostics | Universal transport medium (UTM) | 7.37 (±0.01) | NEG | NEG | NEG | NEG | NEG | |
| Yokon | Universal transport medium (UTM) | 7.44 (±0.01) | NEG | NEG | NEG | NEG | NEG | |
| Gibco | RPMI medium 1640, with HEPES | 7.48 (±0.01) | NEG | NEG | NEG | NEG | NEG | |
| Genesis | KaiBiLi extended ViralTrans, includes HEPES | 7.50 (±0.01) | NEG | NEG | NEG | NEG | NEG | |
| Gibco | Minimal essential media (MEM) | 7.83 (±0.01) | NEG | NEG | NEG | NEG | NEG | |
| Gibco | 1× phosphate buffered saline (PBS), pH 7.4 | 8.20 (±0.01) | NEG | NEG | NEG | NEG | NEG | |
| Abbott | Panbio sample buffer | 8.78 (±0.01) | NEG | NEG | NEG | NEG | NEG | |
| Clinical specimens (n = 120) |
NA | NP swabs in UTM (n = 30) | NA | POSb (28/30) | NEG | NEG | NEG | NEG |
| NA | OP/N swabs in PBS (n = 30) | NA | POSb (26/30) | NEG | NEG | NEG | NEG | |
| NA | BAL samples (n = 30) | NA | POSb (27/30) | NEG | NEG | NEG | NEG | |
| NA | Saline gargles (n = 30) | NA | POSb (27/30) | NEG | NEG | NEG | NEG | |
a
NA, not available; NEG, negative; POS, positive; INV, invalid.
b
Only weak positive reactions were observed.