The determination of ploidy in bacterial cells has been unsatisfactory in most cases because the criteria of ploidy in higher forms can not as yet be applied directly to bacteria. The best evidence of diploidy in bacteria has been in the various \"Het\" strains of Escherichia coli strain K-I2 developed by Lederberg et al. (1951). Unfortunately, genetic recombination has not been found in many bacteria, so this means of ploidy determination has been very limited in use. Genetic and radiobiological studies indicate that bacteria are usually haploid (Lea, 1947); however, several instances have been reported in which cytological information suggests a diploid phase (Bisset, 1950). Lindegren (1942) presented cytological evidence for a meiotic division in Micrococcus orchraceous. Webb and Clark (1954) found evidence of a diploid or polyploid phase in a life cycle of M. aureus. These large cells appeared cytologically to undergo a meiotic division to yield normal haploid cells. This paper is a continuation of the studies of the large, apparently diploid cells of M. aureus.

Ploidy studies on the large cells of Micrococcus aureus.

Enzymatic treatment of bacterial cells prior to staining revealed that the crystal violet nuclear stain reacts with protein components of the nucleus as contrasted to the desoxyribonucleic acid specificity of some nuclear stains.

The site of action of the crystal violet nuclear stain.

Patterns of cell arrangement and nuclear segregation in radiation damaged Micrococcus luteus

The importance of fixatives in the study of internal structures of bacteria is evidenced in papers by Murray (1953), Cassel and Hutchinson (1955), and by Robinow (1956b). The primary purpose of the use of these substances is to maintain, without distortion, the structure and material in the site in the cell where it functioned. In addition, the fixative may in some cases bring about changes in the substrate that are advantageous in staining the material. Few techniques or methods have been available to check the effectiveness of these substances. In this work it is proposed to use the hydrogen chloride method of staining (Chance, 1954) for this purpose. The method does not make use of a fixative prior to staining unless hydrogen chloride could be considered a fixative. This is not likely since in a modified staining procedure the stain can be used before the exposure of the cells to the gas. The distribution and shape of the stained material in cells of air dried smears was apparently a function of exposure to the gas.

Effect of fixatives upon distribution of stainable material in Escherichia coli as shown by hydrogen chloride method of staining.

Herein, a method for thioacetalation using BF3SMe2 is presented. The method allows for convenient and odor-free transformation of aldehydes to methyl-dithioacetals, a simple but sparsely reported structural moiety, in good yields with a diverse set of aromatic aldehydes. In addition, a thiomethylative Friedel-Crafts reaction was discovered, affording thiomethylated diarylmethanes in good to excellent yields. The resulting diarylmethane core is of interest as it is found in many biologically active compounds, and its utility is further demonstrated as a novel precursor to unsymmetrical triarylmethanes. This work also highlights the usefulness and the synthetic capabilities of the readily available reagent BF3SMe2 beyond its reactivity profile as a dealkylation reagent.

https://pubs.acs.org/doi/pdf/10.1021/acsomega.2c07608

Thioacetalation and Multi-Component Thiomethylative Friedel-Crafts Arylation Using BF3SMe2

The crystal violet nuclear stain was compared with the acid Giemsa and thionin-SO2 stains, and it was found that the three technics revealed nuclear structures which were identical. Various methods of fixation and hydrolysis were tested and it was concluded that the crystal violet gave more uniform results if used without fixation or hydrolysis. The effects of these treatments on the other technics are discussed.

R. B. Webb

Papers

A comparison of the crystal violet nuclear stain with other technics.