A new estimation method for plant cell viability by determining electron transport activity.

A new method with which to estimate the viability of tissue-cultured plant cells was developed. In this method, electrons from the electron transport system of Coptis japonica cells were trapped by artificial electron acceptors, and the color of the reduced acceptor was monitored with a spectrophotometer through an optical fiber as surface-reflected light. Cell viability is represented by the amount of increased reflected light per unit time as electron transport activity (ETA). The electron transport activities of cultured Coptis japonica cells that had been effected in viability by the addition of different concentrations of a microbial broth, were related to the ability of the cells to proliferate. When various microbial broths were added to our Coptis japonica cultures, there was a negative correlation between electron transport activity and the amount of berberine released. During usual subculture, electron transport activity increased from the onset of culture, reached a maximum in the late log phase, then decresed rapidly.