Gene silencing is a concept, where a gene product would be negated by the likely usage of interfering RNA’s that would prevent the transcript to be translated.
A double stranded RNA molecule of sense and anti-sense strand could be used in any organism that would selectively prevent the expression of a particular gene product. To test, whether gene silencing is occurring with the double stranded RNA molecule, an embryo is chosen.
The double stranded RNA is injected into the embryo and compared the development of the embryo with the control. If the double stranded RNA injected inside the embryo is highly essential, for the development of the embryo, then silencing of this gene would determine the growth of the test embryo.
Thus, through trial and error method the essential gene could be isolated.