This protocol allows you to clone oligos to generate shRNAs or sgRNAs on a small scale. -For sgRNAs, pXPR vectors with a single BsmBI or BbsI cloning site are most common, two types of pXPR vectors can be used: 1. pXPR_003 (or “lenti guide”) will only contain an sgRNA and is to be used in a cell line that already expresses Cas9. 2. pXPR_023 (also referred to as “lenti CRISPR” or “all-in-one”) already contains Cas9 sequence prior to cloning an sgRNA -For shRNA, pLKO vectors with AgeI / EcoRI cloning sites are most common.