Anti small RNA

Antisense small RNA are short RNA sequences (about 50-500 nucleotides long) that are complementary to other small RNA (sRNA) in the cell. 
sRNAs can repress translation via complementary base-pairing with their target mRNA sequence. Anti-sRNAs function by complementary pairing with sRNAs before the mRNA can be bound, thus freeing the mRNA and relieving translation inhibition.
Function.
Antisense small RNA are found in all of life including Eukaryotes, Bacteria and Archaea. They are non-coding RNA sequences involved in regulatory processes, metabolism, and aiding transcription.
Antisense RNA can also be engineered and utilized by scientists to perform experimental functions.
Identification Methods.
Numerous studies have been performed to identify potential antisense sRNA candidates. Recent experiments have used Northern blot analysis and 5'-end mapping to correctly identify potential antisense sRNA candidates. In 2019, a new algorithm called APERO was established which allows the detection of small transcripts from paired-end bacterial RNA-seq data.  RNA-seq is a popular method used for the identification of small RNA. However, while reliable for eukaryotic sRNA, it remains inaccurate for bacterial sRNA. 
Examples.
AsxR.
AsxR, previously known as EcOnc02, is an anti-sRNA encoded within the 3' region of the "stx2B" gene of "E.Coli" bacteria. It acts to increase expression of the ChuS heme oxygenase via destabilisation of FnrS sRNA. This aids bacterial infection of the animal host gut. 
AgvB.
AgvB, previously known as EcOnc01, inhibits GcvB sRNA repression. Pathogenicity island associated AgvB aids enterohemorrhagic "E. coli" growth at the colonized site within the host animal.