Analyses were made to compare different techniques of pollen extraction and to investigate the pollen contents of East Texas honey. A new alcohol technique for diluting honey is described, and pollen recovery of honey samples diluted with water and alcohol using different centrifugation times was examined. Pollen concentrations of alcohol-diluted samples were significantly higher than those of water-diluted samples. There was no significant difference in the number of pollen taxa recovered between the water long spin technique, and the alcohol technique, however, there was a significant difference between pollen recovery of the water short spin technique versus the alcohol technique. Five samples were compared using the alcohol dilution technique to a new filter technique. No significant difference was found in pollen recovery or concentration values between the two techniques. Pollen counts of 400 or 500 pollen grains yielded significantly more taxa than lesser counts. Taxa in frequency classes remained constant for most pollen types between 200 and 500 grain counts. Variation among five different drops of the same sample was investigated using 200, 300, 400, and 500 pollen grain counts. No significant differences were found in pollen concentration, but each successively higher count had significantly more taxa. Pollen was analyzed from 36 East Texas honeys samples. A total of 431 pollen types (including unknowns) were found. Half of the samples contained between 31-40 pollen types, indicating a diverse botanical flora. Native flora contributed more to East Texas honey than did horticulturalized taxa. All samples, except two, were classified as mixed floral honeys. Berchemia scandens, Salix nigra, and Toxicodendron radicans were found in more than 80% of the East Texas honey samples. Honeys from the northern regions of East Texas are characterized by Berchemia scandens, Ceanothus americanus, Nyssa sylvatica, Rhamnus caroliniana, Salix nigra, and three unknowns. The southern regions are characterized by Mimosa strigillosa, Berchemia scandens, Poaceae, and four unknowns. In general, East Texas honeys are characterized by a combination of Berchemia scandens, unknown 236, Rhamnus caroliniana, and Salix nigra. The most important honey bee floral resources in East Texas appear to be Rhamnaceae, especially Berchemia scandens.

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Centrifugal Separations in Molecular and Cell Biology focuses on the application of modern centrifugation technology in molecular and cell biology, including the separation and fractionation of biological particles by centrifugation on the preparative and analytical scales. The selection first covers the principles and practices of centrifugation and the bases of centrifugal separations. Discussions focus on the basic concepts of sedimentation theory, centrifugation methods, designing centrifugation experiments, care of centrifuges and rotors, and statistical estimation of molecular parameters. The book also ponders on the practical aspects of rate-zonal centrifugation, including gradient materials, density and viscosity of glycerol solutions, and resolution and gradient shape. The publication examines fractionations in zonal rotors and the quantitative aspects of rate-zonal centrifugation. The text then reviews isopycnic centrifugation in ionic media and analytical centrifugation. Topics include separation by isopycnic banding, large-scale preparative procedures, and density-gradient solutes. The selection is a valuable reference for readers interested in centrifugation technology.