The present disclosure is directed to polycistronic guide RNAs, DNA encoding polycistronic gRNA, multiplex CRISPR vectors, a plurality of component DNA fragments for assembly into a DNA encoding a polycistronic gRNA array, a plurality of primer pairs for making a plurality of component DNA fragments to be assembled into a DNA encoding a polycistronic gRNA, and methods of making multiplex CRISPR vectors. The current disclosure is directed to multiplexed CRISPR technologies that have great potential for pathway engineering and genome editing. In the current disclosure describes efficient assembly of tRNA/Csy4/Ribozyme-based gRNA arrays which can be produced in a quick and effective process.