The cells were fixed directly with 10x volumes of methanol at -20°C. The murine tissues were lyzed by pestle in a pH3 citrate buffer or a lysis buffer contaning a RNase inhibitor. The maize roots and shoots were dissociated with dounce homogenizer (20 strokes) in spermidine- or divalent cation-containing buffers supplemented with the RNase inhibitor. The released nuclei from these tissues were filtered through 800-mesh-size nylon membrane, purified using iodixanol density-gradient centrifugation (30%), and fixed in a organic solvent as with the cells. The barcoded cells/nuclei containing cDNA were lyzed. The cDNA were tailed with a PCR handle using TdT. Following second-strand systhesis and preamplification with KAPA HiFi, the cDNA were purified with carboxylic paramagnetic beads in a PEG/NaCl solution. The eluted DNA were tagmenmented with Tn5 and amplified with KAPA HiFi using primers containg P5 and P7 ends and multiplex indices. The amplified products were subjected to size selection, targeting libraries with peaks in the 450bp region.