A variable-light-path-length flow-through cell to be installed on a spectro
photometer was developed for on-line measurement of high cell concentration
s. Cell concentrations of up to about 100 g l(-1) could be measured without
dilution. High concentration of protein solution was also measured. A spec
trophotometer system combined with the flow-through cell is considered to b
e cost effective and durable with a minimal maintenance requirement.