(1)高中《生物》中的实验十一“DNA 的粗提取与鉴定”中所选取的实验材料是鸡血细胞。用鸡血细胞做实验材料进行实验操作,步骤繁琐,实验过程中较难观察到黏稠物出现,在析出 DNA 黏稠物时,很难估计加入蒸馏水的量。因此,为了避免出现上述问题,选用洋葱作实验材料,实验效果显著,具体方法如下:①称取50 g 洋葱,量取5 mL 洗洁精,配制0.015 (1) The experimental material selected in Experiment 11 “Rough extraction and identification of DNA” in the “Biology” high school is chicken blood cells. The use of chicken blood cells as experimental materials for the experimental procedures is cumbersome. It is difficult to observe the presence of viscous substances during the experiment. It is difficult to estimate the amount of distilled water when depositing the viscous DNA. Therefore, in order to avoid the above problems, use onion as experimental material, the experimental results are obvious, the specific methods are as follows: 1 Weigh 50 g onion, measure 5 mL detergent, prepare 0.015