Microsatellite instability (MSI) in SLE LDGs. Representative chromatographic traces for capillary gel electrophoresis analysis of duplex PCR reactions for the quasimonomorphic BAT25 and NR22 microsatellites. The size of the BAT25 amplicon differs between an autologous pair of SLE neutrophils (red line) and LDGs (blue line). The NR22 product was scored as stable in this SLE patient since the primary peak in the LDGs is the same size as the autologous normal-density neutrophils. LDG, low-density granulocyte; SLE, systemic lupus erythematosus.