A 15 year old girl was admitted to the infectious disease hospital with a provisional diagnosis of rabies. The most suitable clinical sample that can confirm the antemortem diagnosis is-
Serum for anti-rabies IgG antibody
Corneal impression smear for immunofluorescence stain
CSF sample for viral culture
Giemsa stain on smear prepared from salivary secretions
For the antemortem diagnosis of rabies, viral antigens can be demonstrated in the corneal smear, skin biopsy from the face or neck or saliva.