Figure 1. Detection of gene-specific RNA in cell-free saliva by RT-PCR. (A) RNA stability in saliva was tested by RT-PCR typing for ACTB after storage for 1, 3, and 6 mos (lanes 2, 3, 4, respectively). Lane 1, molecular-weight marker (100-bp ladder); Lane 5, negative control (templates omitted). (B) GAPDH (B1), RPS9 (B2), and ACTB (B3) were detected consistently in all 10 cases. Lanes 1, 2, and 3 are saliva RNA, positive control (human total RNA; BD Biosciences Clontech, Palo Alto, CA, USA), and negative controls (templates omitted), respectively.