Protocol for siRNA-mediated U1 snRNA knockdown using fluorinated α-helical polypeptide in vitro and in vivo

Here, we present a protocol for small interfering RNA (siRNA)-mediated U1 small nuclear RNA (snRNA) knockdown using fluorinated α-helical polypeptide in macrophages and mouse lungs, providing a dependable approach to silence U1 snRNA in vitro and in vivo. We describe steps for preparing P7F7/siRNA polyplexes and silencing U1 snRNA with P7F7/siRNA polyplexes in macrophages and mouse lungs. Knockdown efficiency is validated through reverse-transcription quantitative real-time PCR analysis. This protocol is applicable for studying the physiological or pathophysiological function of U1 snRNA. For complete details on the use and execution of this protocol, please refer to Zhang et al.¹.