(2) When designing experiments, it is necessary to follow the control principle and the univariate principle. The purpose of this experiment is to explore the effect of paclitaxel on tumor cells, so the univariate is whether paclitaxel exists or not. Paclitaxel was added to group A as the experimental group, and the same amount of normal saline was added to group B as the control group.

(3) The nutrients needed for cell culture in vitro are sugar (glucose), amino acids, growth promoting factors, inorganic salts and trace elements. And natural ingredients such as serum and plasma are usually added;

(4) Changing the culture medium regularly can remove metabolites and prevent the accumulation of cell metabolites from harming the cell itself;

(5) If paclitaxel has anti-tumor effect, the experimental results should be as follows: the number of tumor cells in group A is less than that in group B;

(6) In order to solve the drug source problem of paclitaxel, plant cell culture technology can be used, that is, plant tissue culture technology can be used to dedifferentiate and culture isolated Taxus cells into callus, from which paclitaxel can be extracted and processed.

So the answer is: (1) pancreatin (collagen) disperses tumor cells.

(2) As a control (as opposed to paclitaxel)

(3) Serum (plasma)? Maintain the pH value of the culture solution.

(4) Change the culture medium (regularly)

(5) The number of tumor cells was less than that of group B..

(6) plant tissue culture callus