Preparation Of Mounts Research Articles

Monitoring and contamination incidence of gnotobiotic experiments performed in microisolator cages

With the increased interest in the microbiome research, gnotobiotic animals and techniques emerged again as valuable tools to investigate functional effects of host-microbe and microbe-microbe interactions. The increased demand for gnotobiotic experiments has resulted in the greater need for housing systems for short-term maintenance of gnotobiotic animals. During the last six years, the gnotobiotic facility of the Hannover Medical School has worked intensively with different housing systems for gnotobiotic animals. Here, we report our experience in handling, contamination incidence, and monitoring strategies that we apply for controlling gnotobiotic experiments. From our experience, the risk of introducing contaminants to animals housed in microisolator cages is higher than in isolators. However, with strict operating protocols, the contamination rate in these systems can be minimized. In addition to spore-forming bacteria and fungi from the environment, spore-forming bacteria from defined bacterial communities used in experiments represent the major risk for contamination of gnotobiotic experiments performed in microisolator cages. The presence/absence of contaminants in germ-free animals can be easily monitored by preparation of wet mounts and Gram staining of fecal samples. Contaminants in animals colonized with specific microorganisms need to be tracked with methods such as next-generation sequencing. However, when using PCR-based methods it is important to consider that relatively small amounts of bacterial DNA detected likely originates from food, bedding, or reagents and is not to be interpreted as true contamination.

The using of morphometric indices in the identification of mosquito larvae of the genus Aedes Meigen, 1818 (Diptera, Culicidae) of fauna of Ukraine

As a result of the morphometric analysis on the mosquito larval structures of the genus Aedes Meigen, 1818 from our own collections and literature analyses, a wide variation in quantitative and qualitative indices was revealed. The morphological and metric indices of mosquito larvae are quite similar and vary under the influence of environmental factors, which must be taken into account when determining species. The tables for rapid determination of common mosquito species of Ukraine, with the use of external features that do not require the manufacture of permanent slide mounts, are given in the article. All modern keys for identification are based on dichotomous tables. This process is quite long, does not take into account the individual variability and does not allow the quick identification of species. After analyzing the literature and summing up the result, it can be confirmed that 35 species of bloodsucking mosquitoes of the genus Aedes occur within Ukraine, so there is a need to create a new regional key. The purpose of the study is to propose tables for determining the common mosquitoes of the genus Aedes in Ukraine using external morphometric characteristics. The material used for this study was collected by the author in March–October of 2017–2018 at the territory of Volyn Region. Over the entire study period, a total of 185 samples were collected, 1580 species of mosquito larvae of the genus Aedes were analyzed. During the work, 12 morphometric characters of bloodsucking mosquitoes were used and the results were tabulated to determine species of the genus Aedes. The proposed keys for definition are presented in the form of a tables and have certain advantages, such as, the ability not to take into account the characters lost in the process of collecting or storing and to complete the diagnostics on other features, that is quite problematic with the dichotomous keys, since they have a certain algorithms. The proposed tables are based on the using of quantitative and qualitative external characters and do not require the preparation of slide mounts in further work. There is also the possibility of creating an electronic key, which will greatly facilitate the work on the determination of the larvae in the genus Aedes.

MLA-Based Detection of Organic Matter with Iodized Epoxy Resin—An Alternative to Carnauba

Solid organic matter is an important constituent not only in coal, but also in black shale-hosted ore deposits. The reliable recognition and quantification of organic carbon—as well as its microfabric relation to associated inorganic minerals—plays a crucial role in characterization by scanning electron microscopy-based image analysis. However, the use of conventional epoxy resin in the preparation of grain mounts does not allow for recognition of solid organic carbon compounds. In this study we illustrate that the use of iodized epoxy resin readily overcomes this bottleneck. Best results are obtained with an addition of 15 wt% iodoform to the epoxy resin. With process samples of black shale-hosted polymetallic Kupferschiefer-type ore as a case study, it is shown that recognition and quantification of solid organic carbon are easily achieved and that tangible parameters such as particle and grain sizes, association and liberation for ore and gangue minerals can be determined in the presence of solid organic matter. Due to the inherent uncertainty of the exact chemical composition of the kerogen contained in Kupferschiefer, it was not possible to attain exact comparability between chemical Corg assays and assays calculated from MLA data. However, the results are still found to closely agree with one another. The strength of iodized resin lies in its ability to distinguish organic matter with high hydration ratios in addition to the easy integration in sample preparation. It could therefore be an attractive supplement in the analyses of other raw materials containing complex organic-matter.

Morphological features of Ixodes persulcatus and I. ricinus hybrids: nymphs and adults.

Our aim was to reveal morphological features of first-generation Ixodes persulcatus and I. ricinus hybrids (nymphs and adults) obtained under laboratory conditions for further study of natural populations of these species in sympatry foci. In 65 nymphs of three groups I. ricinus (23 specimens), I. persulcatus (21 specimens), and hybrids (21 specimens), 16 parameters were evaluated (length/width of the scutum and capitulum, length of the hypostome, palp, tarsus I, coxa I, sternal setae, and various scutal and alloscutal setae) and discrimination analysis was performed allowing differentiation of hybrid nymphs from original species. General effectiveness of classification of I. ricinus, I. persulcatus, and hybrids was >95%. Discriminant functions are presented allowing classification of I. persulcatus, I. ricinus, and hybrid nymphs. For description of morphology, 27 adult hybrids (13 males and 14 females) were examined under a stereo microscope at 14-28× (without preparation of permanent mounts). The following morphological distinctions of hybrids from original species were described: posterior marginal groove is not clear (as in I. ricinus) and absence of syncoxa on coxa I (as in I persulcatus). In hybrid males, simultaneous absence of syncoxa on coxa I (as in I. persulcatus) and a long internal spur on coxa I (as in I. ricinus) can be used as a diagnostic feature. Based on the detected characteristics, 10 of 157 ticks collected in Karelia in I. ricinus and I. persulcatus sympatry area were classified as hybrids.

X-ray microanalysis of volcanic ash

The 2010 eruption of Eyjafjallajökull volcano in Iceland demonstrated the disruptive nature of high-level volcanic ash emissions to the world's air traffic.The chemistry of volcanic material is complex and varied. Different eruptions yield both compositional and morphological variation. Equally a single eruption, such as that in Iceland will evolve over time and may potentially produce a range of volcanic products of varying composition and morphology. This variability offers the petrologist the opportunity to derive a tracer to the origins both spatially and temporally of a single particle by means of electron microbeam analysis.EPMA of volcanic ash is now an established technique for this type of analysis as used in tephrachronology. However, airborne paniculate material may, as in the case of Eyjafjallajökull, result in a particle size that is too small and too dispersed for preparation of standard EPMA mounts. Consequently SEM-EDS techniques are preferred for this type of quantitative analysis . Results of quantitative SEM-EDS analysis yield data with a larger precision error than EPMA yet sufficient to source the original eruption. Uncoated samples analyzed using variable pressure SEM yield slightly poorer results at modest pressures.

A new dwarf species, new distribution records, and supplementary descriptive notes of the centipede genus Ityphilus Cook, 1899 (Chilopoda: Geophilomorpha: Ballophilidae) from central Amazonia, Brazil

A new dwarf species of the centipede genus Ityphilus Cook, 1899, named I. donatellae sp. nov. (Chilopoda: Geophilomorpha: Ballophilidae) is hereby proposed on the basis of specimens from the vicinity of Manaus, Central Amazonia (Brazil), previously identified as Ityphilus calinus Chamberlin, 1957 (hereby designated holotype female, paratype male and paratype female). Supplementary morphological data and new illustrations are provided after this type material. The new species, characterized by having the internal edge of the forcipular tarsungulum serrate, is herein included in a key that will enable the identification of the 10 other Neotropical members of the genus Ityphilus sharing the same trait. New distribution records and supplementary descriptive notes for Ityphilus crabilli Pereira, Minelli & Barbieri, 1994, and Ityphilus demoraisi Pereira, Minelli & Barbieri, 1995 (including the first description of the male of the latter), are also given. Undiluted 2-Phenoxyethanol (CAS No. 122-99-6) has been used as an effective clearing agent/mounting medium for the preparation of temporary mounts of all body parts of the examined specimens.

PROJEKTO „MOKYKLOS PATALPŲ ORO MIKROBIOLOGINĖS BŪKLĖS ĮVERTINIMAS“ METODOLOGINIAI ASPEKTAI

The article presents methodological recommendations for the implementation of the project of a microbiological nature. The urgency of the project is undoubted, as it has been noticed that school classes were overcrowded with pupils and almost not ventilated in winter, thus, schoolchildren often suffered from respiratory illnesses. Besides, secondary school programs include many themes in which the concept of microorganisms is used, however, pupils usually lack practical knowledge about isolation of microorganisms in a laboratory and their distribution in the air. The main aim of this work was to evaluate microbial contamination of school premises as well as to provide pupils with knowledge about biological peculiarities of various systematic groups (bacteria, micromycetes and yeast-like fungi) and their macro- and micro-morphological peculiarities. To achieve the aim, the following tasks were set: 1) to develop pupils’ abilities to make experiments and develop their initial skills in research; 2) to form their cognitive experience of the surrounding world while performing team tasks; 3) to develop pupils’ creative-organizational abilities as an integral process of theoretical and practical actions. Due to lack of equipment and conditions, it is not easy to perform microbiological projects in schools. Furthermore, a teacher should have competence, though due to this, in the article much attention is paid to the methods of project performance. Necessary labware and nutritive media for project implementation are indicated. Possible variants of an experiment scheme are discussed and the stages of the experiment are presented coherently. Preparation of microscopical mounts and microscopy methods are described in detail. It is pointed out that the identification of microorganisms is a very hard work, so teachers should be trained in microbiological methods. Handbooks, which can be used for the identification of some microorganisms, are indicated. Much attention is paid to the presentation of experiment results, as pupils participating in the project get much information about microorganisms. Participants get familiarized with the size and shape of bacterial cells and fungal macro-morphological (colony colour, shape, size and colour of colony reverse) and micro-morphological (a shape of conidia and mycelium) peculiarities. Pupils observe reproduction ways of yeast-like fungi (budding and binary fission) and determine yeast cell shape, size and other characteristic properties. While describing microorganisms isolated from school indoor air, pupils indicate a systematic group to which a microorganism (a bacterium, micromycete and yeast-like fungus) belongs. When the opportunities to identify microorganisms exist, pupils point out a genus and a species to which a microorganism is ascribed. Possible variants of systematizing the obtained results (tables and pictures, etc.) are discussed. The implementation of the project in schools has undoubted theoretic and practical significance, because pursuing the project the pupil’s abilities to make an experiment are developed and initial skills in research and cognitive experience of the surrounding invisible world are formed. Execution of the project induces pupils’ creative-organizational abilities as an integral process of theoretical and practical actions. Later the pupils willingly participate in competitions and conferences of young researchers – naturalists, write papers, prepare a wall newspaper about microbial contamination of school indoor air and give recommendations about improvement of school sanitation. While performing team tasks, participants get knowledge about microorganisms of various systematic groups (bacteria, micromycetes and yeast-like fungi), their isolation under laboratory conditions and distribution in the indoor air. Pupils can use obtained knowledge in the lessons of the course “A Man and his Health” (9th grade) as well as in ecology and general biology (11th – 12th grades) lessons. Key words: microorganisms, distribution, air of school premises.

Book Review

Book Review

Tin—lead alloy contamination in polished epoxy grain mounts of heavy minerals

Polished epoxy grain mounts are commonly used for optical analyses of the heavy mineral fraction of unconsolidated sediments. Yet there has been limited discussion of contamination particular to the preparation of epoxy grain mounts. Examination of 116 thin sections under transmitted and reflected light revealed tin—lead and diamond paste contamination in mineral samples from till collected in central New Brunswick. The contamination was found as fracture infillings and as a separate opaque phase with inclusions of other material. Although it has a striking resemblance to naturally occurring mineralization, the contamination was found to have been introduced during the lapping stage of the preparation of the grain mounts. Such contamination must be expected and identified as a preliminary step in heavy mineral analysis. Misidentification of this contamination could result in erroneous conclusions of syngenesis between it and resistant mineral content of the sample. This could be especially problematic in studies of garnet or sulfide mineralogy.

A modified tape-peel technique for preparing permanent qualitative microfossil slides

A method is described for the preparation of permanent microfossil mounts directly transferred from the surface of frozen lake sediment cores. Particulate material is transferred from the freeze dried vertical surfaces of frozen cores and on to microscope slides using transparent adhesive tape and contact cement. The contact cement and organic matter are then removed by combustion and chemical means and the isolated siliceous microfossils fixed in a permanent mounting resin. The technique produces slides with undisturbed sediment stratigraphy and excellent optical quality and permits the study of core microstratigraphy using high resolution phase or interference contrast microscopy.

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.

An improved fungal mounting technique for Nomarski microscopy

The 'sellotape technique' of Butler and Mann (1959) with lactophenol cotton blue stain is widely used in these laboratories for the production of non-permanent fungal mounts for class examination using bright field microscopy. The technique allows very little disturbance of fungal structure for identification and taxonomic work. The major drawbacks of this technique for permanent mounts are the fact that the tape itself is not inert and the adhesive reacts with the lactophenol forming droplets which cover the field of view (Onions et al., l98l). The stressed nature of the tape also gives rise to problems due to interference patterns during Nomarski microscopy. The increasing use of diflerential interference contrast(Nomarski) microscopy in mycological studies prompted a re-evaluation of techniques used in the preparation of fungal mounts. Other types of nonstressed tapes were found but these proved not to be sticky enough to pick up fungal structures from agar media cleanly and without undue damage. The technique described below uses a silicone based adhesive in conjunction with the slightly modified polyvinyl alcohol mountant of Salmon (1954), updated by Omar et al. (1918), and represents a modification and improvement of the technique described by Bretz and Berry (1964).

Preparation of grain mounts

Preparation of grain mounts

Preparation of Grain Mounts: RESEARCH-METHOD PAPER

Preparation of Grain Mounts: RESEARCH-METHOD PAPER

Immunofluorescence and histochemistry of corneal epithelial flat mounts: use of EDTA.

We describe a simple and reliable technique for the preparation of corneal epithelial flat mounts. The technique is based on incubation of corneas or whole globes in an EDTA solution prior to fixation. Corneal epithelial flat mounts prepared by this technique are suitable for study by immunofluorescence or enzyme histochemistry.

A coverslip culture technique for preparing permanent fungus mounts

A coverslip culture technique for the growth of fungi, with subsequent preparation of permanent mounts for microscopic examination, is described. This simplified technique allows examination at different stages of development of the fungus, or can be used in the preparation of large numbers of similar mounts for teaching purposes.

Clay mineral X-ray diffraction analysis; Ag filter-pipette methods

The Ag filter mount method is useful for the low sample weight quantitative study of clay minerals, for their saturation with various cations, for the differentiation between dioctahedral and trioctahedral clay minerals, and for the preparation of random orientation mounts. The pipette mount method is useful for the identification of clay minerals with small particle size in low concentration, especially mixed-layer clays. For routine clay mineral analysis, a combination of both methods is recommended.

The Genus Syrrhopodon in the Americas. II. The Limbate Species

Ten species of Syrrhopodon with the leaves not bordered above by elongated cells occur in the Americas. One species, S. incompletus, is represented by six varieties, including: S. incompletus var. perangustifolius Reese, var. nov.; S. i. var. lanceolatus (Hampe) Reese, comb. et stat. nov.; and S. i. var. bertero- anus (Brid.) Reese, comb. et stat. nov. Keys, descriptions and illustrations are provided for all taxa. This treatment includes all known American taxa of Syrrhopodon with the upper lamina of the leaf not bordered by elongated cells.3 It provides keys, descriptions, il- lustrations, synonymy and discussion of distribution, and is based primarily on herbarium specimens. In it, I have attempted to account for all names applied in the literature to North and South American taxa of Syrrhopodon with the upper lamina elimbate. Observations and measurements were made mostly from specimens mounted in Hoyer's solution (Anderson, 1954). Dry plants of most of the taxa included here, especially those with colored leaf bases, are exceedingly slow to soak up water. Con- sequently, all specimens were first immersed in boiling water before dissection and preparation of permanent mounts.

Quantitative Clay Petrology: The Trees but Not the Forest?

AbstractGravitational settling and centrifuge techniques have been criticized in the preparation of X-ray specimen mounts for quantitative clay petrology because of the marked mineral segregations that can occur. Although the same factors can operate to produce error in the separation of the traditional less-than-2-μm fraction, this potentially more important source of bias is seldom taken into consideration. A fair representation of the bulk sample deserves at least as much attention as a representative X-ray mount. The most accurate and precise X-ray analyses may be geologically misleading or meaningless otherwise and translate as exercises in precision for its own sake.

Preparation of Temporary or Permanent Mounts of Microfungi with Undisturbed Conidia

Preparation of Temporary or Permanent Mounts of Microfungi with Undisturbed Conidia