Instrument: NextSeq 500
Strategy: OTHER
Source: GENOMIC
Selection: other
Layout: SINGLE
Construction protocol: After sorting, cells were washed with PBS, counted, pelleted, and resuspending at up to 5E6 cells per 400 µl of lysis buffer (1% SDS, 50 mM Tris, pH 8, 10 mM EDTA). The remaining protocol reflects additives/procedures performed per each 400 µl of sample. 16µl of NaCl (5M) was added, and the sample was incubated on a heat block overnight at 66°C. The next morning, 8µl of RNAse A (10mg/ml, resuspended in ddH2O) (Zymo, Cat #E1008) was added, and the sample was vortexed briefly, and incubated at 37°C for 1 hour. Next, 8µl of Proteinase K (20mg/ml) (Zymo, Cat #D3001) was added, the sample was vortexed briefly, and incubated at 55°C for 1 hour. A phase lock tube (Quantabio, Cat #2302820) was prepared for each sample by spinning down the gel to the bottom of the tube at 20,000g for 1 minute and then 400µl of Phenol:Chloroform:Isoamyl Alcohol (25:24:1) was added to each tube. 400µl of the sample was then added to the phase lock tube and the tube was shaken vigorously. The sample was centrifuged at maximum speed at room temperature for 5 minutes. The aqueous phase was transferred to a low-binding eppendorf tube (Eppendorf, Cat #022431021) and then 40µl of Sodium Acetate (3M), 1µl GlycoBlue (Invitrogen, Cat # AM9515), and 600µl of room temperature isopropanol was added. The sample was then vortexed and stored at -80°C for 30 minutes or until the sample had frozen solid. Next the sample was centrifuged at maximum speed at 4°C for 30 minutes, the pellet was washed with fresh 70% room temperature Ethanol, and allowed to air dry for 15 minutes. Pellets were then resuspended in Zymo DNA elution buffer (Zymo, Cat No: D3004-4-10), and placed on the heat block at 65°C for 1 hour to completely dissolve the genomic DNA. sgRNA barcodes were amplified from genomic DNA using Takara Ex-Taq polymerase (Takara RR001C), using 40ug of isolated genomic dna as template per sample, following this protocol, https://media.addgene.org/cms/filer_public/61/16/611619f4-0926-4a07-b5c7-e286a8ecf7f5/broadgpp-sequencing-protocol.pdf. PCR amplicons were agarose gel purified using nucleoSpin Gel and PCR Clean‑up Mini kit (Machery-Nagel cat 740609.50) CRISPR sgRNA amplicons