TABLE 1.

RT-PCR detection of MV in filter paper samples after storage under different conditions^a

Storage conditions	Detection after the following storage time (wk):
	1	2	4	8	12	25
20°C, dry	+	+	+	+	+	+
37°C, dry	+	+	+	−	−	NTb
45°C, dry	+	+	−	−	NT	NT
37°C, humidified	+	−	NT	NT	NT	NT

^aEach filter paper (four used) was spotted with 30 in vitro MV-infected B-LCL cells per 25 μl of human blood with EDTA (20 identical spots) and stored dry at 20, 37, or 45°C or in a humidified 37°C incubator. Two 25-μl spots were collected from each filter paper after 1, 2, 4, 8, 12, or 25 weeks of storage, RNA was isolated, and RT-PCR was carried out in duplicate. Results are shown as positive (+) or negative (−), results of duplicate measurements were in all cases concordant. Samples stored for more than 2 weeks at 37°C and humidified could not be processed due to fungal outgrowth. 

^bNT, not tested.