TABLE 1.

Nature and source of sera used in the immunoblot assays

Serum group	No. of samples	Origin of serum samples (n)
Confirmed SARS patient serum (collected 7-60 days after onset of fever)	6	National Environmental Agency, Singapore (1)
		Center for Disease Control, Guangzhou, China (5)
	27	Singapore General Hospital (12)
		Tan Tock Seng Hospital, Singapore (15)
Healthy human serum	66	Singapore General Hospital (10)
		Tan Tock Seng Hospital, Singapore (24)
		Voluntary blood donors in Temasek Life Science Laboratory (32)