Chloroplast elongation factor Tu was purified from Pisum sativum and the binding properties of glutamylated chloroplast tRNAs were studied by gel‐permeation chromatography. Whereas chloroplast Glu‐tRNAGlu is efficiently bound by this factor, the misacylated Glu‐tRNAGin does not interact with chloroplast elongation factor Tu · GTP and is thus efficiently excluded from protein synthesis. Comparison with the behaviour of Escherichia coli elongation factor Tu · GTP shows that this factor, which is not confronted with the in vivo misacylation phenomenon of organelles, binds both Glu‐tRNAGlu and Glu‐tRNAGln from chloroplasts with approximately equal efficiency.

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Complete blood count and differentiation of leukocytes (DIFF) belong to the most frequently performed laboratory diagnostic tests. Here, a flow cytometry‐based method for label‐free DIFF of untouched leukocytes by digital holographic microscopy on the rich phase contrast of peripheral leukocyte images, using highly controlled 2D hydrodynamic focusing conditions is reported. Principal component analysis of morphological characteristics of the reconstructed images allows classification of nine leukocyte types, in addition to different types of leukemia and demonstrates disappearance of acute myeloid leukemia cells in remission. To exclude confounding effects, the classification strategy is tested by the analysis of 20 blinded clinical samples. Here, 70% of the specimens are correctly classified with further 20% classifications close to a correct diagnosis. Taken together, the findings indicate a broad clinical applicability of the cytometry method for automated and reagent‐free diagnosis of hematological disorders.

In the concentration range above 1 mM a linear diffusion-like component of sugar uptake by Streptanthus suspension cells is observed. The rate of permeation is the same for sucrose, glucose, fructose and sorbitol, despite the very different uptake features of these sugars at low concentrations, where sorbitol and sucrose are not taken up at all and where different affinities for glucose and fructose are seen. The linear uptake component is responsible for 80% of sugar uptake at 100 mM, and it is an efficient permeation path for sucrose and fructose, which show poor permeation compared to glucose in the low concentration range. The mechanistic nature of the linear uptake component remains obscure: it is not directly dependent on metabolic energy (uncoupler does not inhibit it) and it is neither saturable up to 100 mM nor is it sugar-specific, but it is changeable, for instance, by plasmolysis or by protoplast generation. The permeation rates are very similar to those found in other plants for the linear component, but are much higher than in artificial membranes. These features are neither fully compatible with diffusion through a lipid phase nor with catalysed transport, and it is therefore suggested that this linear uptake proceeds through hydrophilic domains of the membrane. The linear uptake component will have consequences for apoplastic sugar concentration, sugar-accumulation factors and cell metabolism.

Streptanthus tortuosus Kell. suspension cells will grow in a medium with sucrose as carbohydrate source. It was investigated whether the cells are able to take up sucrose or whether sucrose has to be hydrolyzed to glucose and fructose which eventually are taken up. The detailed quantitative analysis of sugar-uptake rates in the low concentration range up to 1 mM showed the following features: (i) There is definitely no sucrose-uptake system working in the low concentration range; any uptake of radioactivity from labelled sucrose proceeds via hydrolysis of sucrose by cell-wallbound invertase. (ii) Hexoses are taken up by two systems, a glucose-specific system with a K m of 45 μM and a high V max for glucose and a K m of 6 mM and a low V max for fructose, and a fructosespecific system with a K m of 500 μM and high a V max for fructose and a K m of 650 μM and a low V max for glucose. (iii) There is a more than tenfold preference for uptake of the fructose derived from sucrose versus uptake of free fructose, with the result that the kinetic disadvantage of the fructoseuptake system compared to the glucose-uptake system is diminished if sucrose is supplied as the carbon source. It is speculated that invertase might work as an enzyme aiding in fructose transport.