[Differences in the functional activity of human neutrophilic granulocytes in their interactions with semiconductor quantum dots].

The uptake of quantum dots (QD-5 nm particles of CdSe/ZnS-mercaptoacetic acid) by human neutrophilic granulocytes was studied using the methods of scanning laser and scanning probe microscopy. The results show that the neutrophilic granulocytes may be subdivided into three subpopulations: (1) the cells with no uptake of QD (10.0 +/- 2.0%); (2) cells that accumulate QD in their volume (28.0 +/- 1.9%), and (3) cells, surrounded by a halo of QD (59.0 +/- 2.2%). The dispersion of these characteristics may suggest the differences in neutrophilic granulocyte plasma membrane permeability.

[Evaluation of thermal resistance of Azotobacter chroococcum 66 using atomic force microscopy].

A possibility to use atomic force microscopy (AFM) for comparative analysis of thermal resistance of Azotobacter chroococcum 66 cells has been studied. The sizes of bacteria cells and the structuredness of the cytoderm have been shown to vary depending on the dose of hyperthermic action and on the composition of the media for heating and subsequent incubation. A thermally induced increase of a standard roughness parameter (R(a)) and of cell sizes has been revealed to reflect an increased level of their resistance to hyperthermia.

[Scanning probe microscopy for the study of morphological parameters of neutrophilic granulocytes].

Morphological parameters of human blood neutrophilic granulocytes were studied by scanning probe microscopy. The basic morphological characteristics of the living (unfixed) and fixed cells were compared. It was found that using the method described, the dimensions of the cells changed substantially and significantly depending upon the mode of fixation applied. The methanol fixation allowed to demonstrate the internal structure of a cell, though it sharply deformed the object of study. After glutaraldehyde fixation cells possessed the morphological characteristics similar to those of the living cells, but the diameter and height of the fixed cells were again different from those of living cells. The resolution of a scanning probe microscope was higher when the fixed cells were studied, permitting the visualization of a detailed cell structure, including the nucleus and cytoplasmic granules (in particular, when methanol fixation was used). However, this method of study is unreliable for the determination of cell dimensions (diameter and height).