Negative sample testing.

(A) Manual, two-step process used for pooled testing of 32 negative clinical discard specimens. False positive CT results for Fusion® shown (no FPs for Aptima®). (B) Comparison of direct pooling vs 2-step. (C) Automated generation of 200 pools (40 pools of each size) using negative specimens. The manufacturer’s Aptima® cut-off (560 kRLU) and proposed cut-off (350 kRLU) shown. (PNG)</p

Aptima^® performance parameters.

Aptima® performance parameters.</p

PPA between Fusion^® SARS-CoV-2 pooled test results and neat test results from three SARS-CoV-2 assays.

PPA between Fusion® SARS-CoV-2 pooled test results and neat test results from three SARS-CoV-2 assays.</p

Concentrations of heat inactivated SARS-CoV-2 virus used to generate concentrations to measure LLOD.

(DOCX)</p

Distribution of Aptima^® pooled sample test results.

Samples used in manual (left panel) and automated (right panel) pool generation. Test results are represented as circles. Numbers within bars represent median values. Dashed horizontal line represents cut-off value (560 kRLU). Two-sided t-test, * p<0.03, *** p<0.0001.</p

Linearity of the Panther Fusion^® SARS-CoV-2 assay for pooled testing.

(A)(C) Bland-Altman plot and (B)(D) Passing-Bablok regression plots are presented for 5:1 or 10:1 pooled testing versus neat with the Panther Fusion® SARS-CoV-2 assay. For the Bland-Altman plots, the area between the dotted lines (green or orange) indicates the 95% limits of agreement. For the Passing-Bablok regression, the confidence interval is shaded (green or orange) and the blue line indicates the line of identity. The slope and intercept of the regression line are reported in the left top of each panel.</p

Pooled testing schema for testing with Hologic Panther Aptima^® and Fusion^® SARS-CoV-2 assays.

(A) In the two-step process, the negative sample pools were generated first by mixing 4 or 9 samples in equal volume for the 5:1 and 10:1 pooled testing, respectively. From each pool, 400 μL (5:1) or 450 μL (10:1) was transferred into Hologic Panther® SLT tubes, into which 100 μL (5:1) or 50 μL (10:1) of the uniquely identified positive sample was added to obtain the required testing volume of 500 μL for the Hologic Panther® assays. (B) In the one-step process, the negative and positive samples were added directly into the SLT tubes in equal volume. (PNG)</p

PPA of Fusion^® SARS-CoV-2 assay as function of neat Fusion^® C_T.

PPA of Fusion® SARS-CoV-2 assay as function of neat Fusion® CT.</p

PPA of Aptima^® SARS-CoV-2 assay as function of neat Fusion^® C_T.

PPA of Aptima® SARS-CoV-2 assay as function of neat Fusion® CT.</p