Stadler Form Roger Operating Instructions Manual page 50

4.3. Sampling Time Points
Three SKC BioSamplers collected air samples at 1 m height for 10 minutes at a rate of 11.8
l/min at the following time points:
 -10 to 0 min (AS-1)
05 to 15 min (AS-2)

 20 to 30 min (AS-3)
50 to 60 min (AS-4)

Figure 4.1. Sampling scheme for airborne Influenza A illustrating the four Air Sampling (AS)
timepoints used throughout each active and inactive run.
For the active test runs, the air purifier was operated remotely at t = 0 minutes and remained
operating for the duration of the test (Figure 4.1). At the end of the test, the samples were
removed from the BioSamplers and transferred to sterile 40 ml tubes that were immediately
placed on ice and then stored in the laboratory at -20°C until analysis.
4.4. Sample Analysis
Influenza A quantification was performed by ELISA. The ELISA (enzyme-linked
immunosorbent assay) is a plate-based assay technique that uses antibodies with high
specificity to detect and quantify substances, such as peptides and proteins, called antigens.
The NCP-ELISA validated at airmid healthgroup detects and quantifies Influenza A
nucleoprotein (NPA). In this report, the abbreviation "Inf A" is used to refer to the virus
quantified by the ELISA detection of the NPA antigen. The concentration of Inf A in each
sample is reported in this report as ng per m
Virus reduction percentage was calculated according to the formula below:
ASCR092436
of sampled air.
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