A middle-aged man presents with paresthesia of the upper limb in the form of crawling and stinging sensations. His complains started 2 days ago with sleep disturbances. He also has difficulties in drinking fluids. On examination he seems agitated and irritable. Excessive sweating and salivation is present. He also exhibited photophobia and inability to tolerate the draught of the ceiling fan. On the day after admission he develops generalized seizures which are precipitated with light and sound.

His relative gives a history of being bitten by a bat about a month ago and he had not obtained any medical advice for it. What molecular diagnostic test can be performed on the salivary samples to confirm the diagnosis? Source: ZHU, Jian-yong, Jian PAN, and Yuan-qiang LU. Journal of Zhejiang University. Science. 2016.