Touch samples were obtained pursuant to VCU-IRB
approved protocol ID# HM20000454_CR. Volunteers were asked to rub a sterile polypropylene
conical tube (P/N 229421; Celltreat Scientific) using
their palm and fingers for five minutes. Cells were collected from the surface
with sterile pre-wetted swabs (P/N 22037924; Fisher Scientific)
followed by dry swabs. A total of six wet swabs and
two dry swabs were used to sample the entire tube surface. To elute the cells
into solution, the swabs were manually stirred then vortexed for 15 seconds in
10 mL of ultrapure water (18.2 MΩ∙cm). The entire solution was then passed
through a 100 µm filter mesh prior to flow cytometry analysis.
For the two-person mixture samples, each donor
rubbed a tube as described above. The
entire surface area of the tube (excluding the cap) was swabbed with one
slightly wetted cotton-tipped swab followed by one dry swab. The swabs were
then eluted in 2mL of sterile water, vortexed for 15 seconds, and passed
through a 100 µm mesh filter. An 860 µL aliquot of each donor’s touch cell solution was combined to create a 1:1 mixture (by volume) for flow cytometry analysis.
Intrinsic fluorescence measurements were collected on three different flow cytometry instruments- BD FACSAria™ Il flow cytometer, BD FACSCanto™ II Analyzer, and the BD Influx™ Cell Sorter (all from Becton Dickinson, Franklin Lakes, NJ). The FACSCanto and FACS Aria platforms were equipped with 488nm and 633nm
lasers. The Influx cell
sorter was equipped with 488, 561, and 640nm lasers. Channel voltages for the FACS Aria were set as follows: FSC, 200V;
SSC, 475V; APC, 400V. Channel voltages for the FACSCanto were set at Forward Scatter (FSC, 150V), Side Scatter (SSC, 200V) and Allophycocyanin (APC, 250V). Channel voltages for the Influx flow cytometer were set as follows: Forward Scatter (FSC, 17.5V), Side Scatter (SSC,
16V) and Allophycocyanin
(APC, 74.6V).
Flow cytometry source data for all samples are provided in Flow Cytometry Standard (.fcs) format files. Data files are labeled by date of collection, instrument, and Sample ID. Two person mixture samples are labeled with the two donor IDs representing each contributor.