...Once introduced, the puromycin resistance marker encoded in pLKO.1 allows for convenient stable selection...Negative control vector containing scrambled shRNA. psPAX2 Packaging plasmid for producing viral particles...an environment (e.g. BL2+) suitable for handling HIV-derivative viruses. For transient knockdown of protein...Recommended Materials Material Vendor and catalog # psPAX2 Addgene #12260 pMD2.G Addgene #12259 HEK-293T cells... transfection: 1 μg pLKO.1 shRNA plasmid 750 ng psPAX2 packaging plasmid 250 ng pMD2.G envelope plasmid...μg/mL polybrene. TIP: Polybrene increases the efficiency of viral infection. However, polybrene is toxic...drives RNA Polymerase III transcription for generation of shRNA transcripts. cPPT Central polypurine tract,...