An Inexpensive Microscope Lamp for Critical Illumination

A microscope lamp with light of adjustable intensity, which will afford critical illumination of a quality satisfactory for the most exacting cytological work, can be constructed for about $7.50. The essential parts needed are: auto headlight bulb, radio power transformer, radio “potentiometer”, and simple plano-convex lens. A ground glass is not used with 4 and 2 mm. objectives, a solid source of light being obtained by placing the bulb so that one filament coil is directly behind the other. This light source is brought to a focus by the condensing lens at a field diaphragm and this image is projected by the microscope condenser into the plane of focus of the microscope.     

A Golgi-Electron Microscope Method for Insect Nervous Tissue

Golgi's light microscopic method of selective silver impregnation for nervous tissue combined with electron microscopy appears to offer a promising method for working out the detailed anatomy of individual neurons and their connections. Insect nervous tissue is fixed in a mixture of 2% paraformaldehyde and 21/2% glutaraldehyde in Millonig's buffer (pH 7.2) before postfixation for 12 hours in a solution brought to pH 7.2 with KOH containing 2% potassium dichromate, 1% osmium tetroxide and 2% D-glucose. The tissue is then transferred to a solution of 4% potassium dichromate for 1 day; and for 1-2 days to a 0.75% silver nitrate solution. After dehydration and embedding in Araldite, 50μm sections am made. Areas of interest are cut from these sections and re-embedded in silicone molds. Ultrathin sections are then cut and stained with uranyl acetate and lead citrate. The Golgi method described here gives good results at the level of both light and electron microscopy.     

A Rapid Method for Microbial Sample Preparation for the Scanning Electron Microscope

A synthetic aromatic polymer has been used for preparing replicas of different microorganisms. This method of preparing highly concentrated (9.6 k) microbiological samples for scanning electron microscopy was compared with a standard method. The micrographs of the replicated samples are satisfactory. This method is rapid, cost effective and produces good results, especially in the case of spore-forming mycelial microorganisms.     

供光学显微镜观察的花粉样品制备的一种简单方法

传统的制备供光学显微镜观察的花粉样品的方法 (中国科学院植物研究所形态室孢粉组 ,1 960 )不但程序复杂 ,而且不同种类的花粉容易混杂。最近 ,我们在进行山茶属(Ｃａｍｅｌｌｉａ)花粉形态的系统研究中总结出一种制备供光镜观察的花粉材料的简单方法 ,现将其过程介绍如下 :( 1 )从标本或新鲜植株上取下花药 ,用冰醋酸浸软后 ,置洁净的凹玻片 (单凹玻片 )上 ,于解剖镜下将花药打开 ,滴上 95%酒精将花粉洗出。( 2 )滴上预先配制好的分解液 (醋酸酐 9份和浓硫酸 1份 ) ,于室温下或 50℃恒温箱里放置 5ｍｉｎ(具体温度和时间因花粉种类而异 ) …     

The Membrane Method of Electron Microscope Autoradiography

Thin sections of methacrylate and Araldite embedded tissues labelled with radioactive isotopes were transferred with a wire loop or brush from the knife edge onto thin formvar membranes which covered 7 mm holes in 76 × 25 × 1.5 mm or 76 × 38 × 1.5 mm plastic slides. To facilitate the mounting of sections, a platform supported the plastic slides close to the ultramicrotome knife. Photographic emulsion diluted 1:5 or 1:10 with water was applied with a pipette to the upper surface of each formvar membrane to cover the mounted sections. Excess emulsion was drained off and the remaining thin film was dried on a warm plate at 45 C to produce a uniform layer over the sections. After storing in the dark for several weeks, preparations were processed in photographic solutions and washed, and sometimes stained, before applying electron microscope grids to the underside of each formvar membrane. To detach each grid with its adherent formvar, section and emulsion, the membrane was pierced around the perimeter of the grid. Grain counts made over nuclei of cells labelled with tritiated thymidine indicate that emulsion is uniformly distributed over each section and that quantitative comparison is possible between labelled areas.     

A Light Microscope Method for Following the Incorporation of Gluten Into Dough or Other Foodstuffs Containing Different Proteins

It has been shown that gluten powder stained for one minute and forty-five seconds in a 0.192% solution of fast green FCF and then washed repeatedly with distilled water can be detected both by visible light and fluorescence microscopy when incorporated into doughs. Evidence that the functional properties of the gluten are not affected by this treatment suggested that the technique may be useful for following the incorporation of other proteins into various food systems.     

一种用于观察纤毛虫表膜下结构的扫描电镜样品制备新方法

该实验摸索出通过扫描电镜观察纤毛虫表膜下三维结构的新方法:用适当浓度的KMnO_4作为固定剂,固定虫体细胞表膜,调整固定液的渗透压使细胞在低渗溶液中胀破、细胞质溶出,表膜剥落下来、内外翻转,经脱水、冷冻干燥、喷金后,在扫描电镜下对爽口虫(Climacostomumsp.)、尾草履虫(Paramecium caudatum)及拟尾柱虫(Paraurostyla weissei)的表膜下结构进行了观察。结果表明:利用此方法能够观察到表膜下层次分明而又清晰的三维立体构象。此方法可为纤毛虫表膜及其它细胞质膜的研究提供可借鉴的样品制备新方法。     

A Review for Life-history Traits Variation in Frogs Especially for Anurans in China

Environmental variation can promote differentiation in life-history traits in species of anurans. Increased environmental stress usually results in larger age at sexual maturity, older mean age, longer longevity, slower growth, larger body size, and a shift in reproductive allocation from offspring quantity to quality, and a stronger trade-off between offspring size and number. However, previous studies have suggested that there are inconsistent geographical variations in life-history traits among anuran species in China. Hence, we here review the intraspecific patterns and differences in life-history traits(i.e., egg size, clutch size, testes size, sperm length, age at sexual maturity, longevity, body size and sexual size dimorphism) among different populations within species along geographical gradients for anurans in China in recent years. We also provide future directions for studying difference in sperm performance between longer and shorter sperm within a species through transplant experiments and the relationships between metabolic rate and brain size and life-history.     

A New Technique for the Study of Viruses in the Electron Microscope

A method is described for the application of immunochemical stains to virus-infected cells in preparation for examination in the electron microscope. Specific antibodies to viral particles and to purified viral antigens have been rendered visible in the electron microscope by conjugation with the ironcontaining protein, ferritin. Examination of vaccinia-infected and influenza-infected cells treated with their specific ferritin-labelled antiserum has revealed the disposition of mature virus and viral precursors during various stages of the infection. Virus particles maturing at the cell surface and within the cytoplasm were specifically tagged and, in the case of influenza virus, the soluble, nucleoprotein viral-precursor was identified in distinct portions of the nucleus.     

A Precision Hand Trimmer for Electron Microscope Tissue Blocks

The construction and operation of a precision device for hand-trimmiig electron microscope tissue blocks to the pyramidal shape essential to successful thin sectioning are described. The hand trimmer permits very delicate control of the pyramid shaping operation which can be carried out with a speed rivaling or exceeding free-band trimming. It can be utilized with any stereomicroscope provided with epi-illumination.     

A Near Field Microscope in the Tera-hertz Region

This paper reports the study of aexperimental project for two near fieldmicroscopes to operate in the Tera-Hertz(THz) region of the electromagneticspectrum. The first design is suited moreproperly for the millimetre wave region,while the second is addressed to shorterwavelengths, typically below onemillimetre.