Improved enzyme-linked immunosorbent assay for determination of soy protein in meat products.

An indirect, competitive enzyme-linked immunosorbent assay (ELISA) has been developed for quantitation of soy protein in meat products. The methodology allows rapid aqueous extraction of meat samples into a liquid form suitable for assay. The assay is highly specific for soy protein and is designed to measure soy protein levels between 1 and 10% of the wet weight of the sample. Standardized, stabilized reagents for carrying out the procedure are commercially available in a kit. The analysis, including sample preparation, can be completed within a workday, and the actual immunoassay in less than 60 min.

Influence of short term fasting on chicken alimentary canal mucosa.

Little is known about the physiological effects of short-term fasting in avian species. The present study was developed to examine the alimentary mucosal changes in fasted birds by scanning and transmission electron microscopy. Chickens of various ages were fasted for periods of 3, 5, and 7 days. Water was provided ad libitum. At the end of the fasting periods the birds were sacrificed along with ad libitum fed controls. Tissue samples from crop, duodenum, and ileum were processed by standard methods for scanning and transmission electron microscopy (SEM and TEM). The SEM samples were prepared by vacuum drying methods. The TEM samples were embedded in Spurrs embedding medium. Mucosal sloughing was observed in the crop and small intestine with SEM only in fasted birds. With TEM, separation was observed between the mucosal cells of fasted birds with membranous whorls in these spaces. Sloughed cells may be an endogenous protein source for the fasting bird.

A rapid technique for preparing microorganisms for transmission electron microscopy.

A rapid and efficient method of preparing microorganisms for transmission electron microscopy is reported. In developing the method Salmonella, streptococcal, and protozoal specimens were fixed with glutaraldehyde. After fixation cells are collected on a membrane filter, washed with buffer, postfixed with osmium tetroxide, then washed with distilled water and stained en bloc with uranyl acetate. Specimens are dehydrated using a graded series of acetone and then infiltrated with graded mixtures of acetone and Spurr embedding medium. Finally the membrane filter is cut into small pieces and embedded in fresh embedding medium polymerized in polyethylene capsules. By collecting and processing the specimens on membrane filters, numerous centrifugations are eliminated from standard procedures. The use of a low viscosity embedding medium allows for rapid infiltration and embedding of the specimen. Using this technique microbial specimens can be sectioned after less than 4 hours preparation.

Ultrastructure of rumen entodiniomorphs by electron microscopy.

Thin sections of rumen ciliated protozoa of the subclass Spirotrichia were studied by electron microscopy to elucidate their ultrastructure. To prevent retraction of their adoral cilia, menthol crystals were used to relax the retrociliary region. These protozoa had a distinct ectoplasm and endoplasm with the macro- and micronuclei located in the ectoplasm. At the surface of the entodiniomorph body was a highly differentiated cortical zone of four layers. Ribosomes were abundant throughout the cytoplasm, suggesting a substantial potential for protein synthesis. These protozoa appeared to engulf bacteria into large vacuoles, and subsequently the bacteria were taken into the endoplasm in vesicles containing only one bacterium each. The bacteria were digested partially, and only in isolated cases were the bacterial cell walls still intact.

Comparison of tracheal histopathology and scanning electron microscopy of infectious laryngotracheitis.

Samples of trachea were examined with light microscope, fluorescent microscope, and scanning electron microscopy (SEM). Negative controls and infectious laryngotracheitis (ILT) positive samples were compared. Histopathology illustrated lesions characteristic fo ILT. Lesions seen with SEM suggested surface changes including ciliary disruption. luminal debris, epithelial slough, crevices, hemorrhage and exudate. Fluorescence was noted in infected tracheas throughout both trials using fluorescent antibody (FA) technique.

Degeneration of the mucosal surface of the small intestine of the chicken in Salmonella infection.

Day-old chicks were infected with Salmonella typhimurium. The impact on the intestinal mucosa was observed by scanning and transmission electron microscopy. Salmonella infected birds were characterized as having areas on their intestinal mucosal cells devoid of microvilli. The absence of microvilli probably interferes with absorption of the digesta.