Table 3.

Ice nucleation activity (INA) detected in the collection by a droplet freezing assay.

Location	Flight #	# Isolates transferred from sUAS collection	# INA (orig)	% INA (orig)	# INA (rep)	% INA (rep)
Louisiana	LA1	64	6	0.09	0	0
Louisiana	LA2	64	2	0.03	0	0
Louisiana	LA6	64	1	0.02	1	0.02
Louisiana	LA7	64	1	0.02	0	0
Virginia	CF30	40	1	0.03	0	0
Virginia	CF32	16	2	0.13	0	0
Virginia	CF35	30	2	0.07	0	0

A total of 1,963 isolates was screened, and in the first (orig) test, 15 (0.76%) isolates froze droplets at −8°C. Putative ice nucleators were screened again using the same droplet freezing method, and only 1 isolate from Flight LA6 was INA after the second test.