Computational procedures (applicable to desk-top programmable calculators) have been described which are useful in the processing of data generated by transient state isoelectric focusing (TRANSIF) experiments. The system allows the calculation of methological parameters such as peak position, peak separation, segmental pH gradient, resolving power, and resolution. “Apparent” physical constants such as the isoelectric point ( pI), diffusion coefficient ( D), and the slope of the pH-mobility curve ( du d ( pH) ) of amphoteric molecules can be calculated either by linear interpolation ( pI) or by linear regression analysis ( D and du d ( pH) ). The computing programs are also capable of performing operations such as smoothing of raw data, conversion to absorbance, baseline detection and correction, and calculation of the higher statistical moments of Gaussian, bi-Gaussian, and asymmetric peak shapes. Moment analysis is carried out by direct statistical procedures, curve simulation, and slope detection methods. The above computational procedures provide a useful and necessary adjunct to the scanning isoelectric focusing assembly which is coupled to a digital data acquisition and recording system.