Pippin instruments can be used for isolation of microRNA libraries from adapter-dimer content and larger cDNAs.
The Pippin 3% agarose gel cassette was developed for the preparation of miRNA libraries. Adapter-ligated cDNAs of miRNAs (typically 100-170 base pairs depending on the adapter size) can be efficiently isolated away from neighboring adapter-dimers and larger non-miRNA species. Check out citations and posts here.