Idoxuridine

Idoxuridine is a nucleoside analogue, a modified form of deoxyuridine, similar enough to be incorporated into viral DNA replication, but the iodine atom added to the uracil component blocks base pairing.Idoxuridine is used for topical treatment of herpetic eye infections due to herpes simplex virus (HSV)^[2].

The CRFK cells are cultured in 25-cm2 flasks that contained DMEM with 10% FBS. The concentration of idoxuridine is 5, 10, and 50µM. Cells from 1 control flask and 1 flask containing each drug concentration are examined by use of an inverted microscope to detect morphologic changes and evaluate confluence, and cells are then harvested at 24, 48, and 72 hours. Culture medium is decanted, and the monolayer is rinsed once with PBS solution. Cells are then enzymatically detached with trypsin-EDTA solution. Trypsinization is stopped by the addition of DMEM with 10% FBS, and cells are forcefully pipetted to ensure complete detachment from the flasks. Each flask is then rinsed once with DMEM with 10% FBS, and the eluent is combined with the first cell suspension to ensure collection of as many cells as possible from each flask. Cell-containing medium is centrifuged (300 X g for 6 minutes), and the supernatant is decanted. Cells are then resuspended in a known volume of DMEM and counted on a hemacytometer. Cells cultured in each drug concentration at each time point are counted twice, and the total number of cells in each flask is calculated.