GSM9416486: 3350899_2B10_CIITA_2; Homo sapiens; ChIP-Seq
ChIP-seq chromatin preparation was performed using formaldehyde crosslinking. Ten million cells per replicate were crosslinked with 1% formaldehyde for 10 minutes at 37 °C and quenched with glycine. Cells were lysed in SDS lysis buffer, and chromatin was sheared to ~200–500 bp fragments using a Bioruptor sonicator. Immunoprecipitation was performed using target-specific antibodies or IgG control, followed by protein A/G magnetic bead capture, sequential washes, elution, reverse crosslinking, proteinase K digestion, and DNA purification by phenol–chloroform extraction and ethanol precipitation. ChIP and corresponding input DNA libraries were prepared using a KAPA Biosciences paired-end library preparation kit compatible with Illumina sequencing platforms, following the manufacturer's protocol. Library fragment size (~350–450 bp) was verified by Agilent TapeStation. Libraries were normalized, pooled, and sequenced on an Illumina NovaSeq platform using paired-end 50 bp reads.