| Method |
protoplasts are fractionated by forcing them through a nylon net, rupturing them, followed by membrane filters which retain either the released chloroplasts alone or chloroplasts and the mitochondria. By using a small dead space in the filter apparatus, and a rapid flow-rate, the filtrate can be quenched in HC104 about 0.1 s after chloroplast rupture. The parallel assay of metabolites and marker enzyme activities in the filtrates obtained with the net alone or with each of the filter combinations allows the determination of metabolite levels in the mitochondrial, chloroplast, and cytosolic compartments. |