PCR analysis of kappa chain rearrangement.
DNA was isolated from splenocytes using the Dneasy Tissue Kit (Qiagen), with Rnase treatment. PCR reactions contained 100 ng of genomic DNA, 0.2 muM each primer, 0.2 mM dNTPs, and 2.5 U Taq DNA polymerase (NEB) performed in 1X ThermoPol buffer (NEB). Primers used were Vkappacon and Jkappa5-1degrees and have been described previously [74]. PCR conditions were 94 degreesC for 2 min, 40 cycles of 94 degreesC for 30 s, 63 degreesC for 90 s, and 72 degreesC for 1 min, followed by 1 cycle of 72 degreesC for 5 min. 
