< Back to calibration programs In a slope ratio assay the responses of dilutions of a
standard are compared with the responses of dilutions of a test sample. The two lines have an intersection point at dosis = 0 —
the intercept is identical in both equations. 

The SRA presented here is written in
Microsoft Excel and is an copy of the method described by D.J. Finney


Download SRA without visual basic V01mrt2019 
Download SRA with Visual basic V31mrt2019 
The latest version has the possibility to enter 6 responses instead of 4. SRA6x6 V16Aug2021 

The use of the program is straight
forward.
Enter the doses and at least two responses of the sample, the standard and the blanks of the test. The calculated slope is multiplied by predilution and by the calculated potency of the standard. The three Ftests are used to validate the test Blank is to test if the calculated slope intersects with the mean of the blanks Intercept tests if the standard and the sample lines intersect at dosis is zero. curvature test if the line are straight and not curved. If one of these Ftests is greater than the Fcritical the calculated potency must be rejected. 
Reference: "Statistical Methods in Biological Assays" D.J.Finney , Third edition 1978, pag 148166
< Back to calibration programs
Ed Nieuwenhuys,
10 may 2022,
16 august 2021, 9 july 2009