Screening method, screening kit and analysis program

1. A screening method, comprising steps of:

treating lymphoid cells consisting of preliminarily isolated lymphoid cells in culture medium at a temperature in a range from 3° C. to 26° C., with a cytotoxic factor by administering the cytotoxic factor to the lymphoid cells or irradiating the lymphoid cells with the cytotoxic factor;

thereafter incubating the lymphoid cells treated with the cytotoxic factor for a selected time;

measuring after the incubation, a cell size of both living cells and apoptotic cells of the treated lymphoid cells; and

determining an influence of the cytotoxic factor on the lymphoid cells by change in the cell size of the lymphoid cells that have been treated with the cytotoxic factor, with at least one basis selected from the group consisting of (i) presence or absence of shifting of peak part of a cell size distribution, (ii) presence or absence and a degree of a change in a distribution area of the cell size, and (iii) presence or absence and a degree of a change in a cell number of the lymphoid cells having an original size, where the cell size is a size of a whole lymphoid cell, or a size of nucleus of a lymphoid cell, or both,

wherein in the incubating step, the lymphoid cells are incubated in a culture medium supplemented with serum,

the influence of the cytotoxic factor is at least one property thereof selected from the group consisting of toxicity, an effect of a drug, and sensitivity of a specific individual mammal from which or from whom the lymphoid cells are derived,

the lymphoid cells that are influenced with the cytotoxic factor reduce the cell size thereof due to condensation, without forming an apoptotic body generated by fragmentation of the lymphoid cells and without changing a number of the lymphoid cells, and

a total process comprising the treating of the lymphoid cells, the incubation of the treated lymphoid cells, and the measuring after the incubation, is completed within a period in a range from 6 hours to 8 hours.

2. The screening method according to claim 1 ,

wherein the cytotoxic factor is at least one factor selected from the group consisting of radiation, a radiation-protecting agent, an antioxidant, a radiation-sensitizing agent, a drug, and ultraviolet rays.

3. The screening method according to claim 1 ,

wherein the culture medium used in the incubation is a culture medium in which the condensation reduces an area of the lymphoid cells to approximately 70% or less relative to an area of lymphoid cells that have not been treated with the cytotoxic factor.

4. The screening method according to claim 3 ,

wherein the selected time for the incubation is in a range of 6 hours or less.

5. The screening method according to claim 1 ,

wherein in the treating of the lymphoid cells, the cytotoxic factor is administered to or irradiated a plurality of samples of the lymphoid cells at amounts that vary among the samples,

the amounts include at least an amount at which no influence of the cytotoxic factor on the lymphoid cells is expected and an amount at which the influence is expected, and

an amount of the cytotoxic factor that causes the influence is determined.

6. The screening method according to claim 1 ,

wherein in the treating of the lymphoid cells, a plurality of the cytotoxic factors are administered to the lymphoid cells separately, and

sensitivity of the lymphoid cells to each of the plurality of the cytotoxic factors is determined.

7. The screening method according to claim 1 ,

wherein the culture medium used in the incubation is a culture medium in which the condensation reduces an area of the lymphoid cells to approximately 50% or less relative to an area of lymphoid cells that have not been treated with the cytotoxic factor.