Publisher Summary This chapter discusses the procedures employed for the analysis of the sugar components of glycoproteins. Most of the methods used for the estimation of the monosaccharides present in glycoproteins are colorimetric in nature. Because of the relatively low specificity of some of these color reactions, it is often important to apply them only after appropriate separation of the constituents. In many cases complete identification, preferably by chromatographic means, of all the sugar and amino acid constituents of a glycoprotein should precede any colorimetric analysis so that potentially interfering substances may be taken into account. The hydrolytic release of the monosaccharides is also considered in the chapter. The optimal conditions of acid hydrolysis for the monosaccharides vary substantially because of differences both in the stability of their glycosidic bonds and in their susceptibility to destruction during the hydrolysis. One of the prerequisites for an accurate analysis of the monosaccharide components of a polymer is finding hydrolysis conditions under which all of a given sugar is released and yet is not significantly destroyed.

[1] Analysis of sugars found in glycoproteins

Publisher Summary This chapter discusses the chemical analysis of microbial cells. The preparation of material for analysis is discussed, because changes in the chemical composition of cells may occur as a result of the washing and storage conditions used. Wet- and dry-weight determinations of bacterial samples and assay of total cell numbers are described, because analytical results must refer to one or other of these values. Selection of an analytical procedure is a subjective process, because the number of suitable methods is large and each will have different merits and defects. Primary considerations are sensitivity, specificity, reproducibility, and absolute accuracy. Automatic methods for performing biochemical analyses, already widely accepted in hospitals and in industry, are beginning to make their way into the research laboratory. All automatic analyzers developed so far may be classified as either “continuous-flow” or “discrete” types. All of them use colorimetric methods exclusively and contain some form of automatic colorimeter for final read-out. The first and best-known is the Technicon “AutoAnalyzer,” which is of the continuous-flow type.

Chapter III Chemical Analysis of Microbial Cells

Publisher Summary This chapter presents a procedure for the calorimetric analysis of sugars for the identification and determination of small quantities of carbohydrates obtained from biological materials. In general, such tests have been devised by heating aqueous solutions of the sugar with a strong acid, thereby converting it to furfural or a derivative of furfural. A color is then produced by the addition of an organic developer such as indole, orcinol, diphenylamine, or carbazole. Many of the reagents commonly employed for the determination of a specific class of sugars are suitable, with slight modifications, to measure total carbohydrates. Thus, orcinol, carbazole, indole, and diphenylamine have all been used for this purpose. Although these reactions logically require a separate classification, therefore they are discussed individually to prevent unnecessary duplication. For the determination of inulin diphenylamine reaction is employed, which is based on the Ihl-Pechmann reaction for fructose and is not to be confused with the diphenylamine test for DNA. In arsenomolybdate method of Nelson a colorimetric determination of the reaction product replaces the conventional iodometric titration of the reduced copper found in the Somogyi reagent, thus facilitating the handling of serial assays. In addition to the methods discussed in the chapter for the determination of pentoses, there are several alternate procedures which may be of value under special circumstances. The more important of these seem to be the methods of Roe and Rice and of Tracey employing p-bromoaniline and aniline, respectively, as the color-producing agent. These reactions are appreciably less affected by the presence of hexoses and uronic acids than is the case with orcinol.

[12] Colorimetric analysis of sugars

This study was well-received and widely discussed when it appeared in hardback in 1990. It is devoted to analysis of the enduring problem of hunger in the modern world, and of the role that public action can play in countering it. The book is divided into four parts. The first attempts to provide a coherent perspective on the complex nutritional, economic, social and political issues involved in the causation of hunger and deprivation. The second deals with famine prevention, paying special attention to Africa and India. The third focuses on chronic undernourishment and related deprivations. Parts two and three include a number of case studies of successful public action for the prevention of hunger and famines in various parts of the world. The fourth part of the book draws together the main themes and concerns of the earlier chapters, and provides an integrated view of the role of public action in eliminating hunger.

Landrum B. Shettles

Papers

The relation of dietary deficiencies to male fertility.

The living human ovum

The great preponderance of human males conceived.

Ova harvest with in vivo fertilization

Sperm morphology and sex ratios.