Slide Mounts Research Articles

Identification of Hairs of Three Asian Commensal Mammals: Suncus murinus, Bandicota bengalensis, and Rattus exulans

Hairs of 3 major Asian commensal mammals, Suncus murinus (L.), Bandicota bengalensis (Gray and Hardwicke), and Rattus exulans (Peale), were studied, identified, and compared with those of better-known commensal species to provide an overview of their hair morphologies. Techniques were developed for authentic hair specimen collection and rapid slide mounting to aid in the timely analysis of food products. The study showed that hairs of B. bengalensis and R. exulans are easily identified to the regulatory category of "rat or mouse hair," whereas identification of S. murinus contaminant hairs is possible to the species level.

In Situ Hybridization for Detection of HIVRNA

In HIV studies, in situ hybridization can be used for identifying virion RNA, mRNA being produced for virion packaging, and proviral DNA in the cytoplasm or integrated in the nucleus. This unit focuses primarily on identifying virion RNA, because this is the most sensitive means by which in situ hybridization can be employed to detect HIV expression. In situ hybridization, as developed for HIV RNA detection, involves several protocols: (1) preparation of a radioactive or nonradioactive RNA probe; (2) in situ hybridization of probe to cells and paraffin sections of tissue; (3) detection of radiolabeled probe by emulsion autoradiography; (4) development, staining, and mounting of slides; and finally (5) examination of slides by bright-field, dark-field, specular reflectance, or laser-scanning confocal microscopy. The protocols presented in this unit describe a setup involving up to 150 slides.

A Redescription of Types of the Clam Shrimp Eulimnadia agassizii (Spinicaudata: Limnadiidae)

Among the described North American species of the clam shrimp family Limnadiidae, agassizii is poorly known, having been reported from only two localities in extreme southeastern New England. Though recently reported as nonexistent, the original specimens of this species are in the type collection of the Museum of Comparative Zoology, Harvard University. Specific data regarding the collection and an emended and expanded description of the type material are provided, using traditional and contemporary characters, to complement recent studies of the group. In a revision of the Recent Limnadiidae of North America, Belk (1989) discussed traditional characters used to diagnose species and suggested that egg shell morphology demonstrates less intraspecific variation, thus allowing more confident separation of species. Among the several named forms included in his review was agassizii, a poorly known species from southeastern New England. E. agassizii was described (as Limnadia) from Penikese Island in what is now the town of Gosnold, Barnstable County, Massachusetts, by Packard (1874a). Along with a stone plaque and a few obscured foundations, the description of E. agassizii is all that remains of an early attempt to establish a marine biology laboratory on the island (later permanently founded at nearby Woods Hole, Massachusetts). Packard (1883) eventually included E. agassizii in his genus Eulimnadia, first formally proposed as a subgenus (Packard, 1847b). has been recognized by most subsequent authors, although Webb & Bell (1979) reviewed earlier data that suggested overlap in the two taxa and recommended that be synonymized with Limnadia. Additional study is needed to resolve the two views. Belk (1989) remarked that Packard did not leave any type material. In fact, the specimens collected by Walter Faxon on Penikese Island, and certainly the same or part of the same collection used by Packard, exists in the Museum of Comparative Zoology, Harvard University, at Cambridge, Massachusetts. The specimens are labeled as types and are in the type collection but have not been cataloged. No specific holotype was designated. Unaware of the collection, Belk (1989) used specimens of E. agassizii collected in Woods Hole, Massachusetts, to characterize E. agassizii. Though the Woods Hole collection is useful for purposes of comparison with other species, it nevertheless would be useful to provide an accurate redescription of the type collection. Using type material, I redescribe the species below. Variations in certain characters 11 thank Ellie Armstrong-Prosser of the Grey Museum for kindly loaning their collection of agassizii for study. Dr. Denton Belk provided comments on different drafts of the manuscript. TRANS. AM. MICROSC. Soc., 111(3): 223-228. 1992. ? Copyright, 1992, by the American Microscopical Society, Inc. This content downloaded from 207.46.13.11 on Wed, 19 Oct 2016 04:41:46 UTC All use subject to http://about.jstor.org/terms TRANS. AM. MICROSC. SOC. discussed by Packard (1874a,b, 1883) are noted. Egg shell and telson morphology are redescribed based on scanning electron microscopy. MATERIALS AND METHODS The series of specimens examined are distributed among two lots, each designated as part of the type collection. Neither lot is cataloged. The only written record in the collection concerning the specimens is a statement in an accession log dated September 1873, indicating that W. Faxon donated a series of specimens from Penikese Island, Buzzards Bay, Massachusetts. Both lots are preserved in 70% ethanol. The first lot is labeled pool on Penikese Island, Buzzards Bay Mass 27 Aug. 1873 coll. by Walter Faxon. A second label states Eulimnadia agassizii Packard Type!. The lot contains 196 specimens, all females. The second lot is marked Eulimnadia agassizii Type! Penikese Island, Buzzards Bay Aug. 27 1873 W. Faxon. There are six female specimens in the lot. Fourteen specimens were removed from the large lot and used to furnish body parts for light and scanning electron microscopical (SEM) investigations. Body parts used for light microscopy were cleared and mounted in Hoyer's medium, a semipermanent mounting medium. For SEM examination, eggs and entire telsons were dehydrated, coated, and examined with a JEOL model JSM 3500 scanning electron microscope. The drawings of the head are free-hand renditions of slide mounts using an ocular grid to determine key point dimensions. All prepared material, including slides and SEM stubs, was returned to the type collection in the Museum of Comparative Zoology, Harvard University. In addition, specimens of E. agassizii maintained in the collections of the Marine Biological Laboratory (Grey Museum 994), Woods Hole, Massachusetts, collected 9 August 1970 by D. J. Zinn were examined. Nine female specimens are in the collection. Examinations of these latter specimens were limited to use of light microscopy.

Modification of ferrography method for analysis of lymphocytes and bacteria

Problems associated with the analysis of low magnetically susceptible or diamagnetic biological particles in ferrography are related to the unoptimal fluid dynamics, the low magnetic field strength and gradients and the lack of effective magnetizing agents. Flow geometry optimization in slide ferrography has been undertaken with the specific aims of obtaining a thinner flow channel, better-defined fluid flow geometry, uniform distribution of particles within the flowing volume, containment of the flowing liquid sample, exposure of all flowing particles to the magnetic field, and differentiation of deposition layers formed by different forces, i.e. magnetic, gravitation and flow related. These specific aims were attained by adopting a novel slide scheme which at present reduces the fluid flow thickness by tenfold and increases the peak relative magnetostatic force by up to three orders of magnitude, compared with the conventional slide ferrography. The novel slide ferrography scheme, combined with the use of the strongest permanent magnet available, is better suited to the analysis of biological particles than conventional ferrography is. Where native mononuclear blood cells showed no response to the magnetic field when treated with erbium, mononuclear cells which had been cultured for as short as 24 h and as long as 72 h show magnetically induced deposition after erbium treatment. Non-specific labeling with cationized ferritin causes the magnetic deposition of all cells studied, i.e. native and cultured human lymphocytes, and mouse lymphoma cells (YAC-1). Modified slide ferrography shows that the bacterium Escherichia coli has a high affinity for erbium ions and becomes readily magnetized and separated. Observations of bacterial magnetic deposition are possible in unstained slide mounts using scattered light. Scattered-light intensity correlated with the bacterial cell concentration in the samples analyzed by ferrography.

Trace Element Analysis of Solutions at the PPB Level

We have developed a technique to determine the dissolved solid components of water and other liquids by Energy- Dispersive X-Ray Fluorescence (EDXRF) spectrometry. The liquid samples are presented to the spectrometer as small dried spots of the residue remaining after evaporation of the liquid. The dried residues are mounted on thin plastic films cemented to 35 mm plastic slide mounts. Elements from sodium through uranium are detected with detection limits less than one nanogram in favorable cases. Precision of the measurement is better than 2 % relative in favorable cases for secondary-target excitation, and is typically 5 to 10 % for direct excitation given the geometry of the instrument. Detection limits are as low as a part per billion relative to the original liquid for solutions whose total dissolved solid content is 1000 part per million or less.

A Method for Preparing and Staining Histological Sections Containing Titanium Implants for Light Microscopy

An improved method for preparing and staining ground tissue-implant sections for light microscopy is presented. Undecalcified tissue blocks with titanium implants were dehydrated in an ascending series of ethanol and stained in toto with basic fuchsin. Specimens were infiltrated and embedded in methyl methacrylate and sections were prepared using a cutting-grinding-system. The polished surface was counterstained with light green or anilin blue. Light polymerizing resin was used as slide mounting medium and for mounting the coverglass. The sections obtained were 10-15 microns thick with tissue architecture which clearly differentiated structures at the tissue-implant interface. The method was very useful for computer assisted morphometric analysis.

A simple lecture demonstration of flow injection analysis

The difficulties of explaining the basic concepts of dispersion in flow injection analysis are discussed with particular reference to comparisons with segmented flow analysis and high performance liquid chromatography. The problems with diagrammatic illustration of the laminar flow processes and subsequent dispersion of an injected sample zone are explained. A simple demonstration based on a flow cell for a slide projector consisting of a peristaltic pump tube sandwiched between two slightly modified slide mounts is described.

The mounting of stereo slides for projecting molecular models

The mounting of stereo slides for projecting molecular models

Quantitative and densitometric considerations in bas‐relief electron micrographs

AbstractTwo methods for bas‐relief electron micrographs are described, one to produce transparencies for projection and one to produce prints for publication. The basis of these methods is a controlled misregistration of a positive image and a negative image, both on film, to increase contrast and produce a “bas‐relief” effect. This gives the final image a three‐dimensional appearance. No apparent loss of resolution results and no artificial amendment is required. To produce transparencies, a contact film positive is produced from the negative and the two are sandwiched in a slide mount with the appropriate amount of lateral displacement to give the effect. To produce prints, the film positive and the film negative are used to sequentially expose the same sheet of photographic paper prior to development to realize the effect. The bas‐relief induced by the misregistration of the film plates causes apparent shadows and highlights that produce the apparent height that is seen in the enhanced images.

Managanese Oxide Minerals in Nodules of Two Soils of Texas and Alabama

AbstractElemental analyses were made to determine the total Mn and other selected metal elements in the nodules and whole soils of Benchley (Vertic Argiustolls) (Texas) and Decatur (Rhodic Paleudults) (Alabama). Also, DTPA‐extractable Mn in the whole soils was determined as a measure of Mn available to plants. Managanese oxide minerals in soil nodules were magnetically concentrated, and subsequently identified by x‐ray diffraction (XRD), selective chemical treatments and various thermal methods. Tentative identification of one Mn oxide was done by high‐resolution transmission electron microscopy. The greatest concentration of Mn was in the surface horizon of Decatur and in the subsoil of Benchley. Most of the Mn was in the coarser soil fractions. Zinc, Li, Ba, Cu, Mn, and Fe were more concentrated in the nodules than in the respective whole soil. The correlation between DTPA‐extractable Mn and total Mn was high for Benchley and Decatur whole soils. Two Mn oxide minerals, birnessite and lithiophorite, were identified in the nodules of Benchley. Preferred oriented slide mounts and magnetic concentration of the samples aided in Mn oxide identification by XRD. Lattice fringes attributed to todorokite also were observed in Benchley nodules. Lithiophorite was identified in the nodules of Decatur. Other minerals found in the nodules include smectite, kaolinite, quartz, and goethite in Benchley, and kaolinite, quartz, and hematite in Decatur. Calcium, Zn, Li, Ba, and Cu detected in Benchley and Decatur nodules may be part of the Mn oxide mineral structures.

Observations On the Curation of Plant and Soil Nematodes

Observations are made on the curation of plant and soil nematodes by reference to the extensive collection of microscope slides and specimens in the Nematology Department, Rothamsted Experimental Station. Better packaging of specimens in transit is required. The addition of 2 % glycerol to fixatives/preservatives to prevent drying out and aid in the processing of specimens to glycerol is recommended. The cuticles of some nematodes degenerate in TAF fixative which should not be used for long term storage. The metal Cobb-type double cover glass slides are more convenient for transport and storage; a longer base cover glass improves clearance for microscope objectives. Cover glass supports need to be much more extensive than in the past to avoid the eventual flattening of specimens. The wax ring seal/support system is quite effective but a secondary seal and cover glass support are recommended. Immersion oil damages some seals and should be removed immediately after use. The drying out of slide mounts is a problem; specimens keep better in glycerol in vials than on slides. Slide mounts should be adequately and clearly labelled in water/oil-proof ink; type slides should be clearly indicated.

Use of EDTA for palynomorph extraction from evaporites

Presence of palynomorph assemblages that display exquisite preservation in evaporite deposits makes them invaluable as age indicators, as often no other fossils are present. However, such use of palynomorphs has been extremely limited because of complications in extraction from the surrounding rock material. Palynomorphs found in evaporites frequently cannot be removed by conventional uses of hydrofluoric and hydrochloric acids, or by modifications of these techniques (Sittler, 1955; Freudenthal, 1964; and Visscher, 1966), as neither acid is capable of removing significant quantities of sulfate minerals. Inadequate removal of these minerals prevents a good concentration of spores and pollen and hinders the preparation of useful microscope slide mounts.

Larval structures of oxytorines and their significance for the higher classification of some Ichneumonidae (Hymenoptera)

AbstractThe phylogenetic relationships of the Acaenitinae, Oxy‐torinae, and some of their component taxa, especially Cylloceria and Microleptes, are considered in light of new data from larval morphology. The Acaenitinae and Oxytorinae are sister‐groups; the enigmatic oxytorine genus Microleptes is analysed with regard to its larval characters and is placed in to its own subfamily, the Microleptinae. The possibility that the Oxytorinae may be paraphyletic with respect to the Orthocentrinae is discussed. Re‐examination of original slide mounts of last‐instar larval remains has revealed errors in past studies; all previously published material, and several taxa whose larvae were hitherto unknown, are figured.

Using Transparency Film to Produce 35 mm Slides

Using overhead projector transparency film, you can produce 35 mm slides for only a few cents per slide. This can help reduce the number of shots you need to take with your 35 mm camera and consequently lower the overall cost of using slides to enhance classroom instruction. For example, title slides and slides of simple line drawings can be prepared at a very minimal cost. All you need is transparency film, plain white paper (81/2 x 11), a typewriter or pen, a thermal copy machine, slide frames, and an iron. (Slide frames or mounts can be obtained from most photography stores.)

Preservation of Saprolegniaceous Fungi for Light Microscopy

Saprolegniaceous fungi are generally preserved for light microscopy by immersing hyphae in Amann's solution, or less commonly in formalin-acetic-alcohol (FAA) (Seymour, 1970), and mounting specimens on glass slides (Johnson, 1956). Material prepared in this manner is inadequate since the slides cannot be sealed permanently. More importantly, the morphological characteristics of the fungi become distorted (Figs. 1, 2). Thus, key diagnostic features (e.g., antheridial cell shape, mode of antheridial branch attachment, and oogonial wall ornamentation) often cannot be recognized in such preparations. The difficulty in preserving saprolegniaceous fungi has hindered the establish? ment of permanent reference collections of these fungi. Type specimens of most genera have been lost and preserved material, where it exists, is all but useless for taxonomic work. Collections of living cultures (Hawksworth, 1974; Stevens, 1974) are limited and incomplete. Furthermore, living cultures are subject to genetic change (Goos and Pollack, 1965) and can be lost easily as a result of contamination or improper maintenance; they cannot substitute for preserved specimens which provide a permanent record ofthe morphological features pres? ent in an organism at a given time and under specific environmental conditions. A technique has been developed which eliminates most ofthe distortion normally associated with saprolegniaceous fungi preserved by traditional methods. Fungi prepared with this technique can be permanently mounted on glass slides and are suitable for taxonomic studies at the light microscope level. Isolates of Achlya treleaseana (Humphrey) Kauffman, Brevilegnia bispora Couch, and Dictyuchus pseudodictyon Coker et Braxton were grown on split, sterilized hemp seed in glass Petri plates containing sterilized, charcoal-filtered, distilled water. Colonies exhibiting the desired structural features were submerged individually in 1% glutaraldehyde in 0.1 m sodium cacodylate buffer (pH 7.2). After 30 seconds, each colony was transferred and held for 10 minutes in a plate containing 0.1 m sodium cacodylate buffer. This was followed by two 10 minute rinses in distilled water. Colonies were stored in distilled water prior to staining and slide preparation. Permanent slide mount preparations (modified from the method described by Kohlmeyer and Kohlmeyer, 1972) were made by placing a square coverglass (No. 1, 25 mm) in the center of a clean glass slide (76 x 25 x 1 mm). The coverglass and slide were temporarily sealed together by applying a small drop of water at the interface. Portions of mycelium were cut from an intact colony with micro-

Use of Sodium Dodecyl Sulfate (SDS) as a Clearing Agent for Chironomid Larvae Prior to Slide Mounting

Chironomid larvae must generally be made more transparent prior to slide mounting to facilitate the observation of structures utilized in taxonomic identification. We present a new technique for clearing chironomid larvae using sodium dodecyl sulfate (SDS). This technique produces excellent contrast for viewing structures utilized in identification, especially many of the smaller details such as, Lauterborn organs and the antennal blade, that may be obscured by other techniques.

Audio Visual Reviews

Audio Visual Reviews

A Comparison of Four Methods Used to Determine the Diets of Large Herbivores

Esophageal fistulation, stomach content analysis, fecal analysis, and ocular-estimate-by-plot are four of the most publicized methods of determining the diets of large herbivores. The principal objective of this study was to compare the relative values of each of these methods based upon information collected from bi-fistulated (esophageal and rumen) sheep selecting their own forage from a tall-forb community in early summer and late summer, and from confined sheep fed a hand-mixed diet of known composition. Microscope slide mounts were made of plant fragments collected from the esophagus, rumen, and feces of sheep grazing a beauty cinquefoil /velvet lupine Kentucky bluegrass /timothy community in northeastern Oregon. Ocular estimates of forage utilization were made concurrently. Data were converted to percent composition on a dry weight basis for comparisons. Significant differences (p < .05) in percent diet composition among methods occurred for 18 of the 31 plant species consumed in the early summer trial, and for 17 of the 31 plant species consumed in the late summer trial. Diets as determined by the ocular-estimate-by-plot method were generally lower in graminoids and higher in forbs than those as determined by other methods. The esophageal fistula method yielded diets that were lower in graminoids and higher in forbs than diets as determined by stomach content analysis and fecal analysis. Diets as determined by fecal analysis were higher in graminoids and lower in forbs than diets as determined by other methods. In the second study phase, ten confined bi-fistulated sheep were separately fed a dry, ground, hand-composited mixture of orchardgrass, fawn fescue, alfalfa, and ladino clover. The botanical composition of this mixture was determined by microscopic examination of plant fragments and compared to the botanical composition of diets as determined by microscopic examination of esophageal, rumen, and fecal samples. The composition of each of the species contained in esophageal samples was similar to that of the actual diet. Rumen samples were similar to the actual diet only in their composition of orchardgrass, and contained significantly higher (p < .05) amounts of total grasses and significantly lower (p < .05) amounts of total forbs than the actual diet and esophageal samples. Fecal samples were significantly higher (p < .05) in their composition of grasses and significantly lower (p < .05) in their composition of forbs than the actual diet and samples collected from the esophagus or rumen.

A New Method for Recovering Latent Fingerprints from Skin

The developed method for detecting fingerprints on live human skin involves first fuming the suspected area with iodine, and then placing a 35-mm clear plastic strip with a leuco crystal violet coating and a trace of water over the fumed area. A few seconds later a dark purple reproduction of the ridge pattern develops. It is a stable direct positive and can be mounted in a 35-mm slide mount for direct viewing. Readable prints may be obtained up to 1 h after impression on live human skin and two or three lifts may be obtained from the same print.

An Efficient Procedure for Slide Mounting of Larval Chironomids

An Efficient Procedure for Slide Mounting of Larval Chironomids