Table 1.
Sampling time and number of samples in this study.
Fig 1.
The AirDNA system used for air sampling contains portable ventilation fan (PVF) and multi-sheet filter holders.
(A) The AirDNA system used in this study contained portable ventilation fan (PVF) and multi-sheet filter holders. (B) The graphical illustration showing the front view and back view of the C, F, and B multiple-sheet filter holder plates. (C) Side-view illustration showing the multiple-sheet filter holders (C plate, F plate, and B plate) mounted onto the foremost, front, and back positions onto the PVF.
Table 2.
List of primers that used in this study.
Fig 2.
Linear regression line between simulated lower bound of DNA yields at 90% confidence interval and number of filter membranes.
The estimated minimal number of filter sheets for DNA yield of 10 ng is found at an intersection point between the regression line (blue) and the DNA yield value of 10 ng (horizontal red, dashed line).
Fig 3.
(A) Probability of obtaining DNA yield ≥10 ng in indoor location and (B) Probability density of DNA yield by the AirDNA system and MD8 Airport sampler: comparing between indoor and outdoor location. In panel A, indoor samples were used to estimate the probability. In panel B, the probability density plots were shown with both indoor and outdoor data. the Area Under the Curve (AUC) shaded in blue shows the probability of obtaining ≥10 ng of DNA.
Fig 4.
PCR products from air samples indicate (A) amplified 16S rDNA region, (B) amplified 18S rRNA region, and (C) amplified COI region. The left panel showed PCR products visualized by DNA-binding fluorescent dye after agarose gel electrophoresis. DNA lanes labeled ‘AirDNA’ indicate PCR products after using DNA obtained from the AirDNA samples as templates. DNA lanes labeled ‘MD8’ indicate PCR products after using DNA obtained from MD8 Airport samples as templates. H1, H2, and H3 denote the PCR products using DNA templates obtained from the first hour, second hour, and third hour, respectively, of samplings. Lane M indicates DNA ladder. Lane P indicates positive control for PCR products, whereas lane N indicates negative control no template) for PCR products. The right panel of Fig 4 includes box plots showing the intensity levels of PCR bands in each lane. The intensity of PCR product bands after using DNA obtained from AirDNA samples as templates are shown in orange and the intensity of PCR products after using DNA obtained from MD8 Airport samples as templates are shown in blue.
Fig 5.
Importance levels of various air quality variables.
The higher importance levels (closer to 100) suggest that the air quality variables most likely exert large effect on the DNA yields obtained. H1, H2, and H3 indicate sampling done in the first hour, second hour, and third hour, respectively.