A Rapid Method for Macerating Phloem

Sieve cells and sieve tube members can be macerated from the phloem of various organs of woody and herbaceous species by au-toclaving the tissue in a mild macerating medium. This treatment does not digest the primary walls or the callose deposits on the sieve areas and sieve plates of the sieve elements. These cells can then be recognized by the fluorescence of their callose after staining with aniline blue. Sometimes adjacent sieve elements fail to separate and one can observe details of their junctures.     

A Rapid Method for Purification of Oligonucleotides

Abstract

A simple, rapid and novel method for purification of the oligonucleotide using silica gel matrix is described.     

A Rapid lmmunostaining Method for Frozen Sections

A simple and rapid one-step method for demonstrating immunohistochemical markers (leukocyte common antigen, cytokeratin, etc.) is described, which can help define the nature of poorly differentiated neoplasms for diagnosis using frozen section. Microwave irradiation was used to speed immunohistochemical analysis using “Enhanced Polymer One-step Staining” (EPOS) reagents on cryostat sections from a variety of pathologic samples. Reproducible results were obtained using EPOS reagents for leukocyte common antigen and cytokeratin. The overall procedure takes less than 10 min and can be completed during surgery.     

A Rapid Silver-on-the-Slide Method for Nervous Tissue

A progressive silver staining method is described, which permits microscopic examination of the sections during the staining process. After formaldehyde fixation, dehydration and embedding in paraffin or celloidin, fine fibers and synaptic endings may be demonstrated. After formaldehyde fixation and mordanting in 3% K₂Cr₂O₇, myelinated fibers and mitochondria are specifically stained.

The unique feature of this method is, that the silver solution (0.5% protargol) is mixed with the reducing solution: 1.6% Rochelle salts, containing traces of Ag NO₃, MgSO₄, and K₂S (U.S.P.). The sections are placed directly into this mixture, which is then warmed to 45-55° C. Sections are removed when progressive staining is completed, washed in water, dehydrated and mounted.

In the fiber stain, nerve fibers and synaptic endings are dark brown or black, and nuclear chromatin is deep brown, against a pale yellow background. When the myelin sheath procedure is followed, the fiber bundles are deep brown, and the intensity of the staining remains the same for specific tracts, aiding in their identification.     

A Rapid Freehand Sectioning Method for Leaves

For the rapid sectioning of such material as fungus leaf spots a method has been evolved whereby a piece of leaf is soaked in lactophenol and sections are sliced off it, on the slide, under the dissecting microscope, by means of a diagonal scalpel ground with a slightly curved blade. Poor sections can be recognized and removed as soon as they are cut; and it is commonly possible at the same stage to distinguish which sections contain fruiting elements of a fungus.     

A Dynamic Selection Method for Reference Electrode in SSVEP-Based BCI

In SSVEP-based Brain-Computer Interface (BCI), it is very important to get an evoked EEG with a high signal to noise ratio (SNR). The SNR of SSVEP is fundamentally related to the characteristics of stimulus, such as its intensity and frequency, and it is also related to both the reference electrode and the active electrode. In the past, with SSVEP-based BCI, often the potential at ‘Cz’, the average potential at all electrodes or the average mastoid potential, were statically selected as the reference. In conjunction, a certain electrode in the occipital area was statically selected as the active electrode for all stimuli. This work proposed a dynamic selection method for the reference electrode, in which all electrodes can be looked upon as active electrodes, while an electrode which can result in the maximum sum relative-power of a specific frequency SSVEP can be confirmed dynamically and considered as the optimum reference electrode for that specific frequency stimulus. Comparing this dynamic selection method with previous methods, in which ‘Cz’, the average potential at all electrodes or the average mastoid potential were selected as the reference electrode, it is demonstrated that the SNR of SSVEP is improved significantly as is the accuracy of SSVEP detection.     

一种快速提取葱属植物 DNA 的方法

目的：针对分子育种工作的繁琐性及葱属植物次生代谢物较多的特点,研究一种利用普通试剂及简单仪器高效快速提取葱属植物DNA的方法。方法：对碱处理法稍加改进,在碱性环境中高温裂解细胞,将释放的DNA保存在Tris缓冲液中,用PCR检测提取质量并分析DNA的保存时间。结果：与用试剂盒提取的DNA相比,扩增产物无显著差异,利用此方法提取DNA并分析了13个洋葱品种的细胞质雄性不育类型;保存时间分析显示,DNA在常温下只能保存5d,在4℃或-20℃可至少保存2个月。结论：该方法方便快速、成本低、适于田间操作,得到的DNA可满足分子生物学实验的基本要求,可用于以PCR为基础的分子标记辅助育种。     

一种快速、高效花生植株再生体系的建立

快速、高效、重复性好的植株再生体系是转基因育种的基础;本研究以14份不同花生品种的胚小叶为外植体,利用不同激素浓度、组合和不同花生基因型筛选最佳芽诱导培养基、伸长培养基和高效再生基因型。结果表明最佳丛生芽诱导培养基为MSB;＋0．2mg·L-1NAA＋6mg·L-1 6-BA,诱导率为89．50％;最佳伸长培养基为MSB5＋0．2mg.L-1 NAA＋3mg’L-1 6-BA和MSB;＋O．2mg·L～NAA＋4mg·L-1 6-BA＋2mg·L～GA,交替培养,每个丛生芽伸长数达到7．24,时间缩短至3-4周。不同品种再生率的变幅在25．51％～93．01％,大于80％的品种有‘麻油1-1’、‘弗落蔓生’、‘濮花23号’、‘海花1号’。利用‘弗落蔓生’在15周内得到了生根组培苗。     

A Rapid Method for Purifying Bacterial Deoxyribonucleic acid

DNA was purified from bacterial cell lysates by treatment with RNA ase and Pronase followed by chromatography on a column of Sepharose 4B with standard saline citrate buffer as eluant. It has the same base composition as DNA prepared by-Marmur's (1961) method.     

A Rapid Celloidin Method for the Rotary Microtome

A method is described which combines the writer's hot celloidin technic¹ with a form of the clearing-before-cutting procedure. The method requires only 16-17 days and yields a block which may be cut in any microtome, the sections being as thin as those afforded by paraffin with comparable material. The advantages of celloidin over paraffin, listed in the writer's earlier paper, are retained in the present method which, altho consuming more time than the hot process, requires less skill and gives superior results.     

A Rapid Bulk Nissl Method

A simplified and time-saving Nissl method is described in which the fresh nervous tissue is placed directly into: dioxane, 65-70 ml.; water, 15 ml.; 95% alcohol, 20-15 ml.; and toluidine blue, 1 g. This solution fixes, stains, partially clears, and dehydrates in one procedure. The material is then sectioned according to a dry-ice method and mounted on the slide either with or without the use of the rapid albumen procedure. Thus it is possible to terminate an experiment one day and have the tissue ready for microscopic observation on the next.     

A Rapid Method for Making Permanent Mounts of Nematodes

A rapid method which can be used to mount and clear nematodes and their eggs is presented. Permanent mounts of certain nematodes and parasite eggs have been prepared using a medium consisting of 56 parts of a stock solution of polyvinyl alcohol (“PVA”), 22 parts phenol and 22 parts of lactic acid. The stock solution of PVA is prepared by dissolving 15 grams of PVA in 100 ml. of distilled water. This medium can be used on material killed and fixed in 10% formalin, any concentration of alcohol, alcohol-glycerin or glycerin. Results have been very satisfactory in most instances. An accompanying plate of photographs shows some of the preparations obtained by using this method.     

A Rapid and Simple Method for Assaying Interferon1

A new procedure of assaying interferon (IF) has been developed. Cell suspension was dispensed into liquid scintillation counting vials together with IF sample. During an overnight incubation, the cells adhered sufficiently to the bottom of the vials and all the subsequent procedures were carried out without transfer of the cells from the vials. Vesicular stomatitis virus was inoculated and virus-specific RNA was labeled by adding ³H-uridine and actinomycin D to the medium. Incubation was terminated prior to completion of a single-step growth of the virus and radioactivity of the labeled cells in each vial was determined. The reciprocal of the IF dilution which reduced the radioactivity in viral RNA by 50% was taken as the titer. The present procedure consists of simple manipulations and can be completed within 24 hr. Furthermore, it is quite reproducible and gives a titer almost identical to that obtained by the conventional plaque-reduction dose method. The procedure can be applied to mouse L cells, rabbit RK-13 cells and human FL cells, without modification.     

A Rapid Method for Removal of the Spinal Cord

Spinal cords from young (125 g) and adult (400 g) albino rats have been removed from the vertebral column by pressurized hydraulic ejection. Histologic examination of the spinal cords has revealed no structural damage to the tissue. In view of the rapidity and ease of performance, this technique is highly preferable to that of laminectomy in obtaining specimens for routine light microscopy.