Principle 变性和裂解 溶液II(NaOH) NaOH+SDS破碎细胞 (溶液I solution li to break denature and lyses cell 沉淀 solution i to 质粒与染色体 和其它杂质分离 溶液IIl solution iii toneutralize (醋酸的中和作用)19 Principle solution I to resuspend solution II to break denature and lyses cell solution III toneutralize