After washing with PBS, intestines were opened and spread on a bilulous paper. Following two washes using PBS, the intestines were cut into small pieces using a blade, and transferred to 10 mL dissociation buffer [DMEM with 5% FBS, 1% Pen/Strep, 0.25 mg/mL collagenase/dispase (Roche, 10269638001), 0.25 U/mL DNaseI (Thermo Scientific, EN0521), 8 mM EDTA, 0.5 mM DTT] for 30 min incubation at 4°C with gentle shaking. Tissue fragments were collected by removing the supernatant after settling down at room temperature. 10 mL wash buffer (DMEM with 5% FBS, 1% Pen/Strep) was added to the tissue fragment pellet, and followed by firmly shaking up and down for 8 times. After tissue fragment settled, supernatant containing crypts was transferred to a new 15 mL tube for centrifugation at 300 x g for 5 min at 4°C. Crypts were resuspended in 1 mL ACK lysis buffer (Gibco, A1049201) for 3 min incubation at room temperature. 4 mL wash buffer was added to stop the lysing, crypts were collected by centrifugation at 300 x g for 5 min at 4°C. Crypts were digested with 1 mL 0.25% trypsin-EDTA (Gibco, 25200056) at 37°C for 5 min, and the digested was stopped by adding 4 mL wash buffer. Crypts were passed through a 70 μm cell strainer, and intestinal cells were washed in cold PBS twice. Intestinal cell number and viability were evaluated by using an automated cell counter. Approximately 50,000 intestinal cells were collected and washed once with cold PBS at 500 x g for 5 min, 4°C. Cell pellet was resuspended in 50 μL cold lysis buffer (10 mM Tris-HCl, pH 7.4, 10 mM NaCl, 3 mM MgCl2, 0.1% IGEPAL CA-630), and immediately span down at 500 x g for 10 min, 4°C. Tn5 transposase was used for the tagmentation reaction (Illumina, 20034197) at 37°C for 30 min. Fragmented DNAs were purified using a cleanup column (Zymo Research, D4013) and eluted in 10 μL water. All eluted DNA was used as template for a 10 cycles PCR using KAPA-HiFi polymerase (Kapa Biosystems, KK2602) in a 50 μL reaction.