 Through a mechanism whose details are poorly understood, bacteria such as "E. coli" that carry the desired dsRNA can be fed to the worms and will transfer their RNA payload to the worm via the intestinal tract.This "delivery by feeding" is just as effective at inducing gene silencing as more costly and time-consuming delivery methods, such as soaking the worms in dsRNA solution and injecting dsRNA into the gonads.Although delivery is more difficult in most other organisms, efforts are also underway to undertake large-scale genomic screening applications in cell culture with mammalian cells.