For bone marrow subset purification we used B6 RAG1-/-mice to obtain pro-B cells. B6.RAG-/-µ+ mice bearing a rearranged IgM transgene were used to obtain pre-B cells. follicular B cells were sorted from 5-8 week old spleen as CD19+AA4- CD21loCD23hi. Germinal center B cells were obtained from spleens of mice 8 days after IP immunization with 100 mg OVA and 10 mg of LPS in alum. GC B cells were identified as CD19+Fas+GL7+ For each sample 1 - 10 ng of IP material or input control sample was prepared into sequencing libraries using the NEBNext Ultra DNA Library Prep Kit for Illumina following manufacturers protocol. Samples were amplified using 18 cycles of PCR and then size selected on 2% EX agarose gels (Thermo Fisher) and bands cut at 300bps (+ 25 bps) and cleaned up using DNA Clean & Concentrator-25 (Zymo Research). The prepared libraries were loaded onto an Illumina HiSeq2000 for single-end 100 base reads with 7 bases of the index read. Data was processed to generate Fastq files using CASAVA 1.8 and demultiplexed based on index sequences.