Computerized continuous monitoring of cytochemical enzyme reaction product formation by the Vickers M85A microdensitometer

An experimental set-up for the continuous monitoring of cytochemical enzyme reaction rates is described. The design consists of a 32K Commodore PET microcomputer, upgraded to Basic 4 and containing a graphics facility. The microcomputer is interfaced with a Vickers M85A microdensitometer, which has been modified and equipped with a Zeiss X63 water immersion objective. The software allows for the automatic transfer of density readings from the M85A to the microcomputer, and for the continuous monitoring of the enzyme reaction as its proceeds at short time intervals (i.e. down to 3.3 s). The relationship between the absorbance change of the enzyme final reaction product and time is printed both numerically and graphically. Initial velocity rates are calculated by regression analysis, and statistical evaluation of grouped data is possible.