Determination of ED50 in mice by intraperitoneal injection of cartridge arrow toxins
A quantitative response is the intensity of the response in an individual and can be expressed as a continuous value, e.g., blood pressure, urine output, etc. The qualitative response is the appearance of an effect observed in the population, such as life or death, effective or ineffective, etc., and is expressed as the rate or percentage of positive responses (all or nothing, positive rate).ED50 is a parameter of the qualitative response. The dose that causes an effect to occur in half of the individuals in a population is called the half effect size; if the effect is effective, it is the ED50, and if the effect is death, it is the LD50.
Operation method
point-slope method
Principle
The dose that can make half of the individuals in a group show a certain effect is called the half effect size, if the effect is effective, then it is the half effective amount ED50, if the effect is death, then it is the half lethal amount LD50.Therapeutic index = LD50/ ED50 = TI, the bigger the value the better, that is, the more safe the drug is. LD1 , ED99; LD5, ED95 can be obtained by the odds-unit regular method or the point-slope method.
Materials and Instruments
Kunming Breeding Mouse Move 1. Pre-experiment to find the Dmax and Dmin that meet the requirements of the point-slope method described above (5). Positive response criteria: mice fall 3 times within 20 min (note that false positives caused by crowding are excluded). For more product details, please visit Aladdin Scientific website.
Cylindrospermopsin
Wire mesh, wire bench, scales, syringes.
2. After determining the number of groups (n), calculate the dose to be given to each group according to Dmax and Dmin, noting that the common ratio r should be within the above requirements. dmax=rn-Dmin
Calculate the dose that should be injected in each group separately as shown in the table below:
3. Formal experiment:
(1) Screening of mice: Place the mice on the wire mesh and observe them for 10 minutes. Those that can hold on without falling off are qualified and can participate in the experiment. The purpose of this step is to exclude false positives;
(2) Weighing and labeling;
(3) Drug administration and observation: Intraperitoneal injection of the cartridge arrow toxin. Each group was given the appropriate dose separately.
(4) Calculate the positive rate: Positive reaction standard: falling from the wire mesh 3 times within 20 minutes after administration is considered positive.
Example of recording form 1 (for each group)
4. Calculation:
Make a graph with the positive rate as the vertical coordinate and the logarithmic dose as the horizontal coordinate.