Figure 1: Purity of CD19 positive B-cells isolated from mouse splenocytes CD19 positive B-cells were purified from mouse splenocytes using an immune-magnetic bead B-cell isolation method (negative selection). The untouched cells eluted from magnetic column were stained with anti mouse CD19 antibody conjugated with PE and analyzed in flowcytometer. In histogram, bold line represent CD19 negative and grey line represent CD19 positive population of cells.