Commercially Supplied Amine-Modified siRNAs May Require Ultrafiltration prior to Conjugation with Amine-Reactive Compounds
Figure 3
Ultrafiltration dramatically increases siRNA-albumin conjugate yield. (a) SDS-polyacrylamide gel showing outcome of siRNA-BSA conjugation reaction without prior ultrafiltration (lane 4) and subsequent to ultrafiltration of siRNA (lane 5). A 15-fold increase in conjugate band intensity was observed using ultrafiltered siRNA, compared to amine-modified siRNA simply reconstituted in buffer, when scanned at 488 nm. A visible band at the predicted conjugate size was also apparent after staining with Coomassie Brilliant Blue. (b) siRNA conjugation was efficient after buffer exchange with either PBS (pH 7.4) or borate buffer (pH 8). siRNA std : siRNA standard; BSA std : BSA standard.
