Picaridin can be used on human skin or clothing to repel mosquitoes, biting flies, ticks, fleas, and chiggers. These products may be pump sprays, liquids, aerosols, or wipes.
Transcription is carried out by a DNA-dependent RNA polymerase that copies the sequence of a DNA strand into RNA. To begin transcribing a gene, the RNA polymerase binds to a sequence of DNA called a promoter and separates the DNA strands.
RNA interference (RNAi) is a natural process that cells use to 'turn off' or silence unwanted or harmful genes. The initial discovery of this phenomenon was in 1991, by scientists trying to deepen the colour of petunias. Surprisingly, by introducing a gene for colour, they found that they had turned off the gene.