title: Sample S2 Pooled Saliva WGS
design: Saliva was obtained from two consented adults, by forcible expulsion into sterile polycarbonate tubes. Saliva from the two individuals was combined in a 9:1 ratio, and mixed by gentle repipetting. This combined material (300 mL) was manually applied across the entirety of the surface of a UV-irradiated (in house) 3” x 1” glass slide. This was then allowed to air dry in a PCR hood (AirClean Systems, Creedmoor, NC) for approximately 18 hr at room temperature. DNA extraction and purification was performed using the QIAamp DNA Investigator Kit (Qiagen, Germantown, MD, Cat No. 56504). Briefly, sample was collected from the surface of the slide using a swab (4N6FLOQSwabs, ThermoFisher Scientific, Waltham, MA, Cat No. 4479439) dipped first in 1  mL DNase/RNase-free water (Invitrogen, Grand Island, NY, Cat No10977-015). Manufacturer protocol for total DNA extraction from surface swabs was followed. Final yields (~460 ng) were estimated using a Qubit 4 Fluorometer and the Qubit dsDNA HS Assay Kit (ThermoFisher Scientific, Waltham, MA, Cat No. Q33231). To mimic a real-world, surreptitious gathering of samples, aliquots of extracted DNA (~30 ng) were amplified using a multistrand displacement amplification kit (REPLI-g Advanced Single Cell Kit (Qiagen, Germantown, MD, Cat No. 150363) and following, without modification, the included protocol for purified whole genomic DNA amplification.