design: cell line=HEK293T; ATXN2 polyQ tract (CAG repeats) editing sample; polyQ=30Q; method=prime editing (PE); sgRNA(ATXN2)=GGCTTCAGCGACATGGTGAG; NGS amplicon sequencing for polyQ-editing samples; 3 rounds of PCR with barcode addition at the last PCR; agarose gel size selection; PE300 sequencing strategy;