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Articles 3181 - 3210 of 3340
Full-Text Articles in Life Sciences
Morphological Variation Of The Foraminifer Elphidium Excavatum (Terquem) On Crumps Bank And Willoughby Bank, Chesapeake Bay, Virginia, Pamela Kay Painter
Morphological Variation Of The Foraminifer Elphidium Excavatum (Terquem) On Crumps Bank And Willoughby Bank, Chesapeake Bay, Virginia, Pamela Kay Painter
OES Theses and Dissertations
Six variants of the highly variable foraminiferal species, Elphidium excavatum (Terquem) were recognized in the Crumps Bank and Willoughby Bank areas of the southern Chesapeake Bay. Measurements of the size of the test, the number of chambers, the number of umbilical bosses, and the number and average length of the sutural bridges on the last formed chamber, and opaqueness or translucence of the test were made on 30 specimens from each of 36 stations selected for differences in environmental parameters. The measurements were statistically analyzed by discriminant analysis to test the hypothesis that the variants are distinct morphotypes and to …
Factors Effecting Phytoplankton Assemblages In The Lafayette River Estuary, Laurie Ann Kalenak
Factors Effecting Phytoplankton Assemblages In The Lafayette River Estuary, Laurie Ann Kalenak
OES Theses and Dissertations
Chemical and physical parameters were measured with phytoplankton species composition and abundance in the Lafayette River from August to October 1981. Stations located in four distinct areas of the river were statistically analyzed to determine data relationships. Environmental factors considered as potentially influencing the presence and numbers of phytoplankton were salinity, temperature, Secchi depth, tidal phase, orthophosphate, combined nitrates and nitrites, ammonia, and reactive silicates.
The River mouth had higher salinity and nutrient values, with lower temperatures than the other river sections. Diatoms were the dominant cells in this section of the River. At mid-river, salinity and nutrient concentrations decreased, …
Environmental Influence On The Migratory Behavior Of The Brown Shrimp In Pamlico Sound North Carolina, Michael Andrew Matylewich
Environmental Influence On The Migratory Behavior Of The Brown Shrimp In Pamlico Sound North Carolina, Michael Andrew Matylewich
OES Theses and Dissertations
Environmental conditions in the nursery areas during times of development affect the migratory behavior of the brown shrimp (Penaeus aztecus) by influencing growth and natural mortality. A linearized logistic model and a multiple linear model are used to relate environmental factors (week number, water temperature, salinity, air temperature, precipitation, net heating degree days, river discharge) to the cumulative proportion of catch and catch-per-unit-effort, respectively. Multiple regression analysis yielded equations containing the week number, the water temperature and an interaction term as the independent variables. Predictions of total annual yield and total annual catch-per-unit-effort are made using the migratory …
The Effects Of Salinity On Growth And Survival Of The Blue Tilapia Oreochromis Aureus (Steindachner) (Pisces Cichlidae), Maylon Lowell White Jr.
The Effects Of Salinity On Growth And Survival Of The Blue Tilapia Oreochromis Aureus (Steindachner) (Pisces Cichlidae), Maylon Lowell White Jr.
OES Theses and Dissertations
The growth rate of the blue tilapia, Oreochromis aureus, was measured in fresh water, 15 ‰ salinity, and 30 ‰ salinity. The fish were given a hormone-treated feed to sex-reverse the females. Acclimations were achieved by raising the salinity only 5 ‰ per day. A biofilter and frequent water changes were used to maintain water quality in each 40 1 system. Synthetic sea salts were used to achieve desired salinity. The fish were grown for 87 days at 27°-30° C.
So significant difference in growth rate occurred among the three treatments. Salinity did not influence mortalities. All fish appeared to …
The Effects Of Varying Fresh Water Discharge On Dispersion In An Estuarine Hydraulic Model Of The Lafayette River, Norfolk, Virginia, Michael J. Jugan
The Effects Of Varying Fresh Water Discharge On Dispersion In An Estuarine Hydraulic Model Of The Lafayette River, Norfolk, Virginia, Michael J. Jugan
OES Theses and Dissertations
Three experimental tests were conducted in the Lafayette River branch of the Chesapeake Bay Hydraulic Model, each successive test with an increase in the amount of fresh water discharged into the head of the river. This was done to study the response from varying river discharge on mixing parameters including the longitudinal dispersion coefficient (E).
The model generated a tide of constant range and period. Batch releases of Rhodamine WT dye were made in the model and sampled throughout the river for ten tidal cycles. Samples were taken simultaneously at selected high and low water slack.
The calculation of the …
Electroimmunoassay: A New Competitive Protein Binding Assay Using Antibody Selective Electrodes, George Raymond Connell
Electroimmunoassay: A New Competitive Protein Binding Assay Using Antibody Selective Electrodes, George Raymond Connell
Chemistry & Biochemistry Theses & Dissertations
The purpose of this study was to utilize the concept of antibody selective electrodes to developed a new competitive protein binding assay. This is a new concept and a potentially important analytical technique because it combines the advantages of RIA (sensitivity and selectivity) with the advantages of electrical assays (speed and low cost). A conjugate of PGE2 and dibenzo—18- crown-6 (a cation selective ionophore) was synthesized, and incorporated into a plastic membrane. The ionophore conjugate increased the selectivity of a polyvinyl chloride (PVC) membrane to monovalent cations. Transmembrane potential was altered by anti-PGE2 antisera in a concentration dependent …
Isomers Of 5.8s Ribosomal Rna, David Smith
Isomers Of 5.8s Ribosomal Rna, David Smith
Chemistry & Biochemistry Theses & Dissertations
When whole cell RNA was separated by high resolution PAG (i.e., polyacrylamide gel) electrophoresis, 5.8S rRNA migrated as three higher mobility intense bands, and three faint bands of lower mobility. The three intense bands represent conformational isomers which migrated as a single band under denaturing conditions on PAG. The three faint bands represent conformational isomers of a minor form of 5.8S rRNA which is elongated at the 5' terminus of the molecule. This minor form migrates as a single band of lower mobility than the major form when electrophoresed on a denaturing PAG. The minor form was determined to have …
Feeding Behavior Of Three Species Of Spionid Polychaetes, Thomas Lane Stokes Jr.
Feeding Behavior Of Three Species Of Spionid Polychaetes, Thomas Lane Stokes Jr.
Biological Sciences Theses & Dissertations
Observations of feeding behavior of three species of spionid polychaetes (Paraprionospio pinnata, Polydora ligni, and Streblospio benedicti) were performed in currents ranging from 0 to 10 cm/sec over fine and coarse sediments and in high and low suspended particle loads. These interface feeders may suspension feed, deposit feed, or both simultaneously using a pair of anterior tentaculate feeding palps. P. ligni and S. benedicti were found to alter their palp behaviors in response to experimental manipulations. P. ligni reacted strongly to currents by suspension feeding with coiled palps. S. benedicti reacted strongly and complexly to food particle type and availability. …
Variation In Leaf Macronutrients Of Overstory Trees As Influenced By Species Season And Soil Type In The Great Dismal Swamp Of Virginia, Bruce J. Bandle
Variation In Leaf Macronutrients Of Overstory Trees As Influenced By Species Season And Soil Type In The Great Dismal Swamp Of Virginia, Bruce J. Bandle
Biological Sciences Theses & Dissertations
Leaf macronutrient variation was studied in four plant communities in the Dismal Swamp of Virginia. composition differed markedly between these sites. Soils and species Eight important overstory trees were studied in August 1980; whereas red maple (Acer rubrum L.} and black gum (Nyssa sylvatica Marsh.}, which occurred on all four sites, were sampled seasonally. Significant differences (p .05) were found in the nutrient concentrations of the leaves between species, seasons, and sites. These differences may be attributed to inherent species characteristics, leaf expansion, nutrient translocation, and differences in soil organic matter content, pH, and degree of …
Electroimmunoassay A New Competitive Protein Binding Assay Using Antibody Selective Electrodes, George Raymond Connell
Electroimmunoassay A New Competitive Protein Binding Assay Using Antibody Selective Electrodes, George Raymond Connell
Chemistry & Biochemistry Theses & Dissertations
The purpose of this study was to utilize concept of antibody selective electrodes to develop a new competitive protein binding assay. This is a new concept and potentially important analytical technique because it combines the advantage of RIA (sensitivity and selectivity) with advantages of electrical assays (speed and low cost).
Development Of A Procedure For Analysis Of High Density Lipoprotein Subclasses, Chan Chin
Development Of A Procedure For Analysis Of High Density Lipoprotein Subclasses, Chan Chin
Chemistry & Biochemistry Theses & Dissertations
Human serum high density lipoprotein subclasses, HDL2 and HDL3 , were isolated by preparative salt density gradient ultracentrifugation and further analyzed by electrophoresis on a 4 to 15% concentration gradient polyacrylamide gel.
The separation of the major classes of serum lipoproteins was achieved after a single ultracentrifugation for 272,000 g at 15°c in a swinging bucket rotor. High resolution concentration gradient gel electrophoresis was found to be particularly suitable for the separation of lipoproteins. The isolation of HDL by precipitation methods, heparin-manganese and dextran-magnesium have also been evaluated in this study, and were found not to completely separate …
Determining The Uptake And Possible Assimilation Of The Plant Component Of Spartina Detritus By Palaemonetes Pugio Using A Rapid Radiolabeling Method, Michael Peter Crosby
Determining The Uptake And Possible Assimilation Of The Plant Component Of Spartina Detritus By Palaemonetes Pugio Using A Rapid Radiolabeling Method, Michael Peter Crosby
Biological Sciences Theses & Dissertations
Assimilation of the plant components of Spartina alterniflora detritus by the grass shrimp, Palaemonetes pugio, was investigated in a laboratory feeding study. A new radiolabeling procedure was utilized to label the sterilized detritus with 14C. Organic carbon values were calculated for both S. alterniflora and P. pugio. The grass shrimp were found to assimilate significantly the detritus, with an assimilation efficiency of approximately 14%, and an approximate ingestion rate of 2.508 x l0-4mg C detritus/mg C shrimp hour-l occurred. It is hypothesized that coprophagous activity may be important to the completion of digestion of …
The Effects Of Kepone On The Estuarine Copepod Acartia Tonsa, Judith Marie Wilson
The Effects Of Kepone On The Estuarine Copepod Acartia Tonsa, Judith Marie Wilson
Biological Sciences Theses & Dissertations
Due to the contamination of a 113 km reach of the James River, Kepone poses a serious environmental threat to the Chesapeake Bay. The purpose of the study is to determine the acutely toxic and sublethal levels of kepone for the copepod Acartia tonsa, and to investigate what effects those levels may have on filtration rates.
Kepone was determined to be acutely toxic to A. tonsa, with a 96 hour LC50 of 4.96 ug/1. Dunaliella tertiolecta was selected as the food source for the grazing experiments. Kepone concentrations of 0.046 ug/1 significantly (0.05 level) reduced the flltering rate …
Development Of An On-Line Computer System For Enzyme Kinetics Studies, Jacqueline R. Thweatt
Development Of An On-Line Computer System For Enzyme Kinetics Studies, Jacqueline R. Thweatt
Chemistry & Biochemistry Theses & Dissertations
The PDP-11/10 minicomputer was interfaced to the Beckman 25 ultraviolet/visible spectrophotometer and this on-line computer system was applied to enzyme kinetics studies. This interface involved hardware equipment to locate, amplify, and transmit the analog signal to an analog-to-digital converter, and software to acquire and store the digital data. Data processing programs were used to calculate kinetic parameters and statistical information from the acquired data.
The Varian Cary 219 ultraviolet/visible spectrophotometer can be readily interfaced to the Apple II Plus microcomputer by hardware equipment which can be purchased from the manufacturer. Various software may also be purchased for use in enzyme …
An Ecological Study Of The Troglobitic Cirolanid Isopod Antrolana Lira Bowman From Madisons Saltpetre Cave And Stegers Fissure, Augusta Co., Virginia, T. Lynn Collins
An Ecological Study Of The Troglobitic Cirolanid Isopod Antrolana Lira Bowman From Madisons Saltpetre Cave And Stegers Fissure, Augusta Co., Virginia, T. Lynn Collins
Biological Sciences Theses & Dissertations
An ecological study of the troglobitic cirolanid isopod, Antrolana lira Bowman, was begun in August 1979 and continued through September 1980. The isopod is restricted to two phreatic lakes in Madisons Saltpetre Cave and one phreatic lake in nearby Stegers Fissure, Augusta Co., Virginia.
All three phreatic lakes were scuba dived and surveyed. No direct connections were found between the lakes. However, physical similarities suggest that the lakes are made up of the same body of phreatic water.
Random samples were taken monthly and seasonally from the east lake in Madisons Saltpetre Cave and the lake in Stegers Fissure. Specimens …
A Comparison Of Recruitment Strategies Among Brachyuran Crustacean Megalopae Of The York River, Lower Chesapeake Bay And Adjacent Shelf Waters, David Franklin Johnson
A Comparison Of Recruitment Strategies Among Brachyuran Crustacean Megalopae Of The York River, Lower Chesapeake Bay And Adjacent Shelf Waters, David Franklin Johnson
OES Theses and Dissertations
Twenty-one stations forming a transect of the Pamunkey River, York River, lower Chesapeake Bay and adjacent coastal waters were sampled from July through September 1980. The megalopa stages of 11 brachyuran species were sampled. Vertical and horizontal distributions are described for each species in relation to salinity and water column stratification. The megalopae are assigned to three apparent recruitment strategies: retained estuarine, expelled estuarine and retained coastal megalopae. the megalopa stages of estuarine adults, such as Hexapanopeus angustifrons, Neopanope sayi, Panopeus herbstii and Pinnotheres ostreum, are retained in estuarine epibenthic waters, while Rhithropanopeus harrisii are retained in slightly shallower …
Ortho Cyclization Reactions Of Catecholamines, Robert Lee Hudkins
Ortho Cyclization Reactions Of Catecholamines, Robert Lee Hudkins
Chemistry & Biochemistry Theses & Dissertations
A study was undertaken to examine the potential for ortho cyclization associated with the synthesis of 1,2,3,4,-tetrahydroisoquinolines using the Pictet-Spengler reaction. Specif1cally, the condensation of the biogenic amines, dopamine, norepinephrine and epinephrine were carefully examined in light of current literature and the facility and extent of ortho cyclization in each case. The para isomers of these three biogenic amine condensation products were isolated and characterized, while only the ortho isomer derived from dopamine was found stable and could be isolated, and structurally identified. These studies demonstrate that a second cyclization product does, in fact, form in each instance and that …
A Laboratory Study Of Nongenetic Embryonic Adaptation To Salinity And Its Subsequent Effects Upon Larval Development Of The Grass Shrimp Palaemonetes Pugio Holthius, Paul Jay Anninos
OES Theses and Dissertations
Fertilized embryos of the grass shrimp Palamonetes pugio Holthuis (Decapoda; Caridea) were exposed to two levels of salinity [5 ppt (exposed) and 20 ppt (control)] during incubation to determine the extent to which embryonic adaptation influences subsequent larval development. Larval response to embryonic exposure was measured at three salinities (5 ppt, 10 ppt, and 20 ppt) as the fraction of larvae surviving to metamorphosis and the duration (in days) of larval development. The survival rate of larvae hatched from control, or non-adapted, embryos was significantly influenced by rearing salinity. The differences in survival of pre-adapted larvae (exposed group), however, were …
Food Habits And Ecology Of Beavers In Southeastern Virginia, John Lennox Echternach Jr.
Food Habits And Ecology Of Beavers In Southeastern Virginia, John Lennox Echternach Jr.
Biological Sciences Theses & Dissertations
The food habits and ecology of three beaver colonies in James County, Virginia were studied. Vegetation surrounding the colonies was characterized as southern mixed hardwood forest or lowland swamp forest. Stream flow values ranged from 0.013 to 0.369 m3/sec. Water depth ranged from 0.5 60 4.0 m. Caloric value of 13 heavily used woody species ranged from 3305 to 6204 cal/g. Considerable seasonal variation was noted in most species with the lowest caloric values noted in summer. No relationship was found between caloric value and frequency of use. Fresh cutting was monitored on a weekly basis and a …
A Structural Analysis Of Phytoplankton In The Chesapeake Bay Plume And Adjacent Shelf Waters, Charles K. Rutledge
A Structural Analysis Of Phytoplankton In The Chesapeake Bay Plume And Adjacent Shelf Waters, Charles K. Rutledge
Biological Sciences Theses & Dissertations
Community structures of phytoplankton populations from the southern portion of the Chesapeake Bight were examined and associated to real and environmental spaces. The sampling design was specifically intended to examine the small scale three dimensional structure of the Chesapeake Bay plume as characterized by its phytoplankton populations. The phytoplankton were sampled at 101 stations, non-synoptically, over a five day period in mid-June, 1980.
Several multivariate numerical techniques were used to determine the relationships between the phytoplankton species distributions and pattern the low salinity plume distribution. A pattern of distribution which approximated the salinity plume resulted from several clustering procedures. Environmental …
Electron Microscopic Demonstration Of Neural Connections Using Horseradish Peroxidase: A Comparison Of The Tetramethylbenzidine Procedure With Seven Other Histochemical Methods, Keith A. Carson, M-Marsel Mesulam
Electron Microscopic Demonstration Of Neural Connections Using Horseradish Peroxidase: A Comparison Of The Tetramethylbenzidine Procedure With Seven Other Histochemical Methods, Keith A. Carson, M-Marsel Mesulam
Biological Sciences Faculty Publications
Eight methods for the electron microscopic demonstration of horseradish peroxidase (HRP) labeling have been compared in adjacent series of vibratome sections of mouse lumbar spinal cord. The tracer, a HRP-wheat germ agglutinin (WGA) conjugate, was injected into the gastrocnemius muscle complex. Following retrograde axonal transport to the lumbar motor neurons and transganglionic anterograde transport of the tracer to the dorsal horn, the HRP activity was demonstrated in eight series of adjacent sections of lumbar spinal cord using eight methods. These included procedures using tetramethylbenzidine (TMB), benzidine dihydrochloride (BDHC), o-tolidine, paraphenylenediamine-pyrocatechol (PPD-PC), and 4 methods using 3,3'-diaminobenzidine (DAB). All eight methods …
Organic N-Chloramines: Chemistry And Toxicology, Frank E. Scully, Jr., Maxwell A. Bempong
Organic N-Chloramines: Chemistry And Toxicology, Frank E. Scully, Jr., Maxwell A. Bempong
Chemistry & Biochemistry Faculty Publications
The stability of aqueous solutions of organic N-chloramines, suspected of contaminating chlorinated water, has been studied. Two factors influence the decomposition of solutions of N-chloropiperidine and N-chlorodiethylamine: a spontaneous decomposition and photodecomposition. Since solutions of these compounds are relatively long-lived, a need for an analytical method for their identification is discussed. A new method is described which involves reaction of organic N-chloramines with arenesulfinic acid salts. The method gives high yields of stable arenesulfonamides. Several toxicological studies of N-chloropiperidine are described. The compound is mutagenic by Ames assay in Salmonella typhimurium strain TA 100 and does not require metabolic activation …
An Evaluation Of Nutrient Sources To Onslow Bay, North Carolina, Larry P. Atkinson, Leonard J. Pietrafesa, Eileen E. Hofmann
An Evaluation Of Nutrient Sources To Onslow Bay, North Carolina, Larry P. Atkinson, Leonard J. Pietrafesa, Eileen E. Hofmann
CCPO Publications
Hydrographic and current meter data from Onslow Bay, North Carolina, were examined to determine the relative importance of various nutrient sources.
Upwelled Gulf Stream water is the major source of nutrients while rivers represent a minor, if not insignificant, source. In the summer during stratified conditions, the upwelled water penetrates across the shelf, but in the winter the upwelled water is restricted to the outer shelf. Nitrate flux across the 40 m isobath was calculated from continuous temperature and current records. Flux during the summer of 1976 was 2 μM m2 sec-1 which is considerably less than flux …
Myology And Osteology Of Lupinoblennius Herre (Pisces: Blenniidae), William A. Roumillat
Myology And Osteology Of Lupinoblennius Herre (Pisces: Blenniidae), William A. Roumillat
Biological Sciences Theses & Dissertations
Certain osteological characters of the genus Lupinoblennius Herre (Pisces: Blenniidae) indicate that it is a specialized member of the tribe Blenniini. Two of these characters are similar to those reported in more advanced tribes. Unifying this genus with the Blenniini are certain muscle patterns that appear unique for the tribe. A comprehensive description of blenny musculature is presented to correct previous literature misinterpretations, and to lay the groundwork for future infrafamilial comparative anatomical studies.
Small Mammals In Openings In Virginia's Dismal Swamp, Robert K. Rose
Small Mammals In Openings In Virginia's Dismal Swamp, Robert K. Rose
Biological Sciences Faculty Publications
In a study of small mammals of openings in the Dismal Swamp of Virginia, seven species were obtained using pitfall traps. Samples included several species rarely caught in the Swamp - seven specimens of the Dismal Swamp subspecies of the southern bog lemming, Synaptomys cooperi helaletes, the first collected in this century; two least shrews, Cryptotis parva; and 15 southeastern shrews, Sorex longirostris fisheri . Results are compared to previous studies, conducted primarily in forested habitats, in which the white-footed mouse, Peromyscus leucopus, and the golden mouse, Ochrotomys nuttalli, were numerically dominant.
Correlation Between Glutathione Peroxidase Activity And Selenium Concentrations In Both Plasma And Erythrocytes, Agatha Dudzai Munyanyi
Correlation Between Glutathione Peroxidase Activity And Selenium Concentrations In Both Plasma And Erythrocytes, Agatha Dudzai Munyanyi
Chemistry & Biochemistry Theses & Dissertations
Plasma and erythrocyte glutathione peroxidase activities and selenium concentrations were determined for 38 apparently healthy female subjects. In addition, erythrocyte lead and plasma lead and iron concentrations were determined in each subject.
Effects of age, smoking, vitamin and mineral supplementation, use of caffeinated beverages and oral contraceptives on glutathione peroxidase activity were determined and interelement relationships were investigated using the one tailed t-test and Spearman Rank Correlation Coefficients
The Effects Of Copper On Skeletonema Costatum (Greville) Cleve, Susanne Sybille Jackman
The Effects Of Copper On Skeletonema Costatum (Greville) Cleve, Susanne Sybille Jackman
Biological Sciences Theses & Dissertations
Copper levels and dominant phytoplankton species composition were examined from six sites in Kings Creek on Virginia's Eastern Shore from March to August 1980. Creek copper levels were determined by an APDCMIBK extraction procedure and ranged from 0.003 to 0.020 mg/1. Diatoms were the dominant phytoplankters with Skeletonema costatum (Greville) Cleve emerging as a major late summer species.
Subsequent laboratory studies involved 96-hour experiments using Skeletonema costatum (clone Skel) grown in enriched natural seawater. The water was collected from Kings Creek and enriched to Guillard and Ryther's (1962) f/2 media levels. Cupric sulfate was added to the experimental culture media …
A Quantitative Description Of Migratory Behavior Of The Brown Shrimp (Penaeus Aztecus) With Applications In Fisheries Management, Anne Madolyn Babcock
A Quantitative Description Of Migratory Behavior Of The Brown Shrimp (Penaeus Aztecus) With Applications In Fisheries Management, Anne Madolyn Babcock
OES Theses and Dissertations
A quantitative description of the migratory behavior of the brown shrimp, Penaeus aztecus, was established using the density approach. A theoretical time density was estimated by the proportion of catch and catch per boat hour NOAA-NMFS fisheries statistics collected in Pamlico Sound, the Neuse River, and Core Sound. A clear quantitative description of brown shrimp migratory timing is found in the time densities. The impact of various physical tactors on the progress of the fishery in time and space can be objectively evaluated by using the time density statistics as dependent variables in modeling efforts. The distributions also enable …
Algal Dynamics In A Cypress Stand In The Seasonally Flooded Great Dismal Swamp, Joseph A. Atchue Iii
Algal Dynamics In A Cypress Stand In The Seasonally Flooded Great Dismal Swamp, Joseph A. Atchue Iii
Biological Sciences Theses & Dissertations
The dynamics of epiphytic algae and phytoplankton were studied at a cypress stand in the Great Dismal Swamp, Virginia. Mean epiphytic algal biomass was 19.9 g m-2 and mean planktonic biomass was 3.4 g m-2.Nutrient concentrations in the epiphytic algae and the litter were determined. The algae had mean concentrations of 1.67% and 0.18%. They were found to immobilize as much as 0.5 g N m-2 and 0.06 g P m-2. This suggests that the algae are important as nutrient conservers. The phytoplankton were composed primarily of Bacillariophyceae. They exhibited a more or less …
In Vitro Enzymatic Assay Of Rna Methylation, Pamela Jean Eubanks Gallup
In Vitro Enzymatic Assay Of Rna Methylation, Pamela Jean Eubanks Gallup
Chemistry & Biochemistry Theses & Dissertations
An assay procedure for in vitro enzymatic methylation of mannnalian ribosomal RNA has been developed in this study. The assay procedure, utilized for the comparison of normal and neoplastic methylase activities (using mouse liver and Ehrlich ascites cells as sources of enzyme), is a modification of previously published methods (52,53). A 100,000 x g supernatant (SlOO) enzyme preparation was incubated with 28S-5.8S rRNA and tritium-labeled S-adenosyl-L-methionine. The RNA was extracted, applied to DEAE cellulose paper, washed, and the radioactivity counted. The neoplastic cell methylase preparation was more active in methylating both exogenous neoplastic and normal 28S-5.8S rRNA than the normal …