[42] Two simple programs for the analysis of data from enzyme-linked immunosorbent assays (ELISA) on a programmable desk-top calculator

This chapter discusses two simple programs for use with an inexpensive programmable calculator that rapidly and accurately converts raw data generated from enzyme-linked immunosorbent assays (ELISA) directly into antigen concentration. The first program computes and compares effective doses (ED50) between a standard and each unknown sample assayed. The (ED50) from the unknown sample is then multiplied by a concentration factor that yields the unknown concentration. The second program linearizes the sigmoidal enzyme-linked immunosorbent assay titration curve using a logit-log transformation of the data, in order to compute unknown concentration values. Both the programs employ stringent limit conditions to decrease “nonsense” calculations. Data is then processed by a least-squares best-fit linear regression analysis. While these programs have been designed for use with a competitive fibrinogen ELISA (that is, absorbance is inversely proportional to the amount of antigen in a well), both may be used with direct (that is, absorbance a [antigen]) ELISA test systems.