Shelf-life of citric acid-toluidine blue O-SO2 and its influence on Feulgen staining.

The paper reports on the preparation of a dye-SO2 reagent employing a Schiff-type dye, toluidine blue O. The method is to replace 5 ml of N HCl per 100 ml of the dye solution by citric acid. The usual potassium metabisulphite is then added. The pH of this new modified dye-SO2 reagent is 2.5 as against 1.6 for the hydrochloric acid-toluidine blue O-SO2. The shelf-life of this newly developed dye-SO2 reagent is four weeks with appreciable reduction of staining intensity after this period as compared with that of a freshly prepared dye-reagent with N HCl. A possible interpretation for the observed phenomenon has been suggested.     

Demonstration of DNA with an extra-sensitive Schiff's reagent and a Schiff-type dye-reagent, toluidine blue O-SO2

This paper describes a method for the preparation of Schiff's reagent as well as a Schiff-type dye-reagent, toluidine blue O-SO2 for use in Feulgen procedure. The method involves replacement of the usual N HCl by N H2SO4 and the usual amount of potassium metabisulphite. Following this method of preparation, an extra-sensitive Schiff's reagent is obtained which requires only 4-5 min for optimum nuclear colouration even when staining is performed at 5 degrees C. This Schiff's reagent produces perfect Feulgen staining up to 6 months after preparation. Toluidine blue O-SO2, prepared with N H2SO4 and potassium metabisulphite, also produces perfect Feulgen type staining of the DNA-aldehyde molecules of acid-hydrolysed mammalian tissue sections. Toluidine blue O-SO2 when shaken with activated charcoal and filtered produces very satisfactory result. The shell-life of this dye-reagent is just a week. The suitability of the use of N H2SO4 for the preparation of Schiff's reagent as well as a Schiff-type dye-reagent, toluidine blue O-SO2, has been discussed.     

Staining of DNA-phosphate groups and DNA-aldehyde molecules with dyes of the azine group

The investigation reports on the use of safranine-SO2 and phenosafranine-SO2, prepared with N HCl or oxalic acid plus potassium metabisulphite, for staining rat liver sections following Feulgen procedure. It has been found that optimum staining of DNA-aldehyde molecules is possible with safranine-SO2 and phenosafranine-SO2, prepared with N HCl and potassium metabisulphite, upto a duration of one week after the preparation of the dye-reagents. Thereafter, staining intensity of the nuclei produced by the dye-reagents is gradually diminished. Staining of acid-hydrolysed sections is also possible with aqueous solutions of these dyes. Moreover, DNA-phosphate groups can also be stained with aqueous solutions of these dyes after selective extraction of RNA with cold phosphoric acid. The in situ absorption spectra of nuclei, stained for DNA-aldehyde molecules with safranine-SO2, phenosafranine-SO2 and aqueous solutions of these dyes, have been presented in this paper. Also presented herein are absorption data of nuclei stained with these dyes after selective extraction of RNA. It has been found that absorption-peaks of nuclei stained differently are different from one another. The implications of these findings have been discussed.     

Specific staining of nuclei with aqueous solutions of celestin blue B and gallocyanine

This paper presents methods for specific staining of nuclei with aqueous solutions of celestin blue B and gallocyanine in tissue sections from which RNA has been extracted selectively with concentrated phosphoric acid at 5 degrees C for 20 min or by hydrolysis in 6 N HCl at 28 degrees C for 15 min. It has been found that pH of the freshly prepared celestin blue B dye solution is 3.0 and that of an aqueous solution of gallocyanine is 2.8. These pHs can be lowered to 1.5 with concentrated sulphuric or nitric acid and at this pH staining of the nuclei is possible. But with concentrated sulphuric or nitric acid and at this pH staining of the nuclei is possible. But if the pHs are lowered with concentrated hydrochloric or phosphoric acid, effective use of these dyes is not possible. It has been suggested that some dispersion of the two dyes takes place with concentrated sulphuric or nitric acid which are used to lower the pH. Staining of the nuclei is also possible with an aqueous solution of celestin blue B at pH 3.0 but the same is not possible with gallocyanine at pH 2.8. The absorption spectra of nuclei stained with an aqueous solution of celestin blue B at pH 1.5 and 3.0 are fairly identical, the peak of maximum absorption being at 620 nm. Those of nuclei stained with an aqueous solution of gallocyanine reveal irregular peaks. Possible implications of these findings have been discussed.     

Propionic acid-metabisulphite-Schiff reagent for quick Feulgen staining

This communication presents a method for the preparation of Schiff reagent in which N hydrochloric acid has been replaced by a low concentration of propionic acid. The result of using such a Schiff reagent indicates that the dye-reagent thus prepared is extrafast in action on acid-hydrolysed mammalian tissue sections. The intensity of nuclear colouration is also increased considerably, since the pH of the dye-reagent is 6.0. It is, therefore advocated that this newly developed Schiff reagent be used at 5 degrees C.     

离子排斥色谱法分析饮用矿泉水中总碳酸盐

利用阳离子交换分离柱对弱酸阴离子具有离子排斥作用这一分离机理,以稀盐酸(0.1mmol/L)为淋洗液,抑制型电导检测,直接进样快速测定饮用矿泉水中的碳酸盐.结果显示,该方法具有良好的线性(r=0.99999)和精密度(0.4336％,n=l0),回收率为99.1％～103.52％,最小检出浓度为0.86mg/L.     

Use of tris-buffer-fortified thionine-SO2 for detection of DNA-aldehyde following Feulgen procedure

This communication presents informations on the use of tris-buffer along with N HCl and potassium metabisulphite for the preparation of thionine-SO2 in staining DNA-aldehyde molecules of acid hydrolysed mammalian liver sections. It has been found that thionine, containing tris-buffer, N HCl and potassium metabisulphite, stains DNA-aldehyde molecules with better result than is possible with the control dye-SO2 reagent that does not contain this buffer. The absorption spectra of nuclei stained with this dye-reagent prepared with tris-buffer have also been presented. Further, it has been found that nuclei stained with the freshly prepared dye-SO2 reagent is bluish-violet, whereas those stained with an old dye-reagent is sky blue in colour. The reason for the slightly enhanced nuclear colouration with the experimental dye-reagent over the control has been considered to be due to slightly increased pH in the former as compared with that of the latter. The mechanism of staining with thionine-SO2 has been considered to be of Feulgen type.     

A rapid procedure for the staining of chromosomes in fixed animal materials

This paper presents a very simple and reliable procedure for the staining of animal chromosomes employing dyes, such as pyronin G, acridine red, rhodamine B, rhodamine 3GO, belonging to aminoxanthene group and brilliant cresyl blue and methylene violet 3RD, belonging to quinone-imine group. The procedure has been tried on sections of the grasshopper and mouse testes fixed in Dutt's modification of Nawaschin mixture. The method is to deparaffinise sections and then to stain with aqueous solution of these dyes for 2--3 minutes, rinsed with water and dehydrated through grades of ethanol, keeping for 15--30 seconds in each grade with several dips. Preparations are then cleared in xylene and mounted. Stained preparations following this procedure revealed excellent colouration of the chromosomes at all the various stages of mitosis and meiosis, particularly in the case of the grasshopper. Mouse chromosomes stained with these dyes following the same method revealed perfect colouration of the fully condensed chromosomes at all stages of mitosis and meiosis but not of the very early stages, except the sex chromosome. Moreover, grasshopper testis sections when treated with cold concentrated phosphoric acid for varying time-periods and then stained with these dyes also revealed excellent colouration of the chromosomes. The implications of these findings have been discussed.     

Use of aqueous solutions of two basic dyes for the demonstration of DNA

This paper presents informations as to the ability of aqueous solutions of two basic dyes, such as Dahlia and Victoria blue, belonging to aminotriarylmethane group for the staining of DNA-aldehyde molecules as well as DNA-phosphate groups. It has been found that sections of rat tissues stained with aqueous solutions of these dyes after acid hydrolysis followed by drying between folds of filter paper and treatment in n-butanol for a minute and then by a very brief treatment in a mixture consisting of equal parts of n-butanol and absolute ethanol reveal well-stained nuclei. Tissue sections after acid hydrolysis when stained with aqueous solutions of these dyes and then treated with SO2 water do not reveal any colouration of the nuclei. Since both the dyes are without any primary amino group in their molecules, it has been concluded that the imino group of Dahlia and the tertiary amino group of Victoria blue with cold concentrated phosphoric acid and then stained with any of these dyes also exhibit well-stained nuclei. The absorption spectra of nuclei stained with these dyes for DNA-aldehyde molecules as well as DNA-phosphate groups reveal positions of the peaks of maximum absorption at the same wavelength, which, however, are different in the case of nuclei stained with the two dyes. The implications of these findings have been discussed.     

In situ demonstration of DNA with Schiff-type dyes prepared with meta-phosphoric or tartaric acid

A new method for the preparation of azure A-SO2 and safranine-SO2 For use in Feulgen procedure has been described herein. The method involves the use of m-phosphoric acid or tartaric acid in place of N HCl in the preparation of these eye-reagents which exhibit enhanced pH producing increased staining intensity of the nuclei as compared with those of the controls, prepared with N HCl. Possible explanation for the increased staining intensity as well as the reason for the shorter shelf-life of these eye-reagents have been offered.     

Detection of DNA in mammalian tissues following removal of RNA with cold phosphoric acid.

The paper deals with the staining of nuclei in mammalian tissue sections with night blue, belonging to diphenylnaphthylmethane group and is devoid of any primary amino group in its molecules but is provided with a secondary amino group and tertiary amino groups. Staining of the DNA-phosphate groups with an aqueous solution of night blue depends upon selective removal of RNA from formalin-fixed mammalian tissues by the use of cold concentrated phosphoric acid for 20 min or 75% phosphoric acid in the cold for 2 h. Moreover, sections from which RNA has been extracted can be hydrolysed in 6N HCl at room temperature for 15 min and then can be stained with the aqueous solution of the dye. Sections of tissues after only acid hydrolysis and staining also reveal very satisfactory staining of the nuclei. Possible mechanism of staining has been suggested.     

镍基合金复合涂层耐蚀性的研究

研究了真空熔烧镍基合金复合涂层在40％NaOH、10％H2SO4溶液、10％HCl溶液及36％NaCl溶液中的耐蚀性。结果表明,复合涂层在4种溶液中都具有良好的耐蚀性。腐蚀出现在硬质相与镍基基体之间,属晶间腐蚀。     

Influence of UV rays on Feulgen-type staining with azure A-SO2 prepared with normal hydrochloric acid and sodium thiosulphate

This communication presents a new method for the preparation of azure A-SO2 for use in Feulgen procedure. The salient feature of this method lies in the fact that azure A-SO2 can be decolourised with normal hydrochloric acid and sodium thiosulphate. The pH of this dye reagent is 2.3 and it is of water colour after filtration. The pH of this dye-reagent is raised to 4.0 with an aqueous solution of sodium hydroxide. Nuclear colouration with this newly developed dye-reagent on acid-hydrolysed DNA of tissue sections becomes fairly satisfactory under the usual laboratory conditions. Staining with this dye-reagent under exposure to UV ray is, however, vastly improved within 5 minutes as compared with the control. Stained sections do withstand treatment in SO2 water without exhibiting any leaching of the dye from the nuclei. Possible mode of action of UV rays in increasing the intensity of staining as well as the speed of reaction has been suggested.     

Air-drying of human leucocytes for scanning electron microscopy using the GTGO procedure

The utilization of tannic acid and guanidine hydrochloride as mordants for better osmium binding has been shown to serve as an excellent alternative to metal coating of organ tissue specimens for scanning electron microscopy (SEM). The present report describes the GTGO procedure, a modification of the TAO technique introduced by Murakami et al. (1977, 1978), which we have found successful for the preparation of air dried peripheral blood leucocytes for SEM studies. Air dried, GTGO-treated leucocytes show excellent preservation of surface features with minimal cell shrinkage. When critical point dried, GTGO-treated cells are examined, they also show less shrinkage than cells prepared with standard glutaraldehyde fixation and critical point drying. The potential application of this air drying procedure (GTGO-AD) to other soft biological specimens is currently under investigation. This technique is recommended as a new and effective air drying procedure for the successful preparation of cells for SEM.     

Surface textures and process characteristics of the electrolytic photoetching of annealed AISI 304 stainless steel in hydrochloric acid

Electrolytic photoetching of AISI 304 stainless steel surfaces in 10% (w/w) hydrochloric acid has been studied. A surface texture value of 1.35 μm ($\text{R}{}_{\mathrm{a}}$) has been measured for a commercially acceptable rate of etch (10 μm/min). Comparisons of this etching system with FeCl₃-HCl-H₂O spray systems used in conventional photochemical machining have also been made     

Chromoxane cyanine R. I. Physical and chemical properties of the dye and of some of its iron complexes

Chromoxane cyanine R (Colour Index No. 43820, Mordant blue 3; also known as eriochrome cyanine R and solochrome cyanine R) is a valuable biological stain. The dyestuff is supplied as a powder containing a little less than 50% by weight of the monosodium salt of the dye, mixed with colourless crystalline and amorphous fillers. The tetrabasic colour acid was prepared and purified for study of the chemical and spectral properties of the dye. Chromoxane cyanine R is an acid-base indicator, with five different colours corresponding to the colour acid and the four anions. The most conspicuous colour change, from yellow to blue, occurs with ionization of the phenolic hydroxyl group at pH 11–12. The dye is assayed by measuring the absorbance of a strongly alkaline solution at 585 nm, with reference to a standard solution prepared from the purified colour acid. Spectrophotometric evidence has been found for the existence of three dye-metal complexes in solutions of the dye containing added ferric chloride at pH 1·5 (the pH of iron-dye solutions most useful in histological staining). These have the postulated compositions [Fe₂H(dye)]-(red), [FeH₂(dye)]- (red), and [Fe₂(dye)]^2- (blue). The first two are probably simple carboxylate complexes of low stability. Increase in pH or molar iron:dye ratio promotes formation of the more stable blue complex, which is a metal chelate. Other blue complexes have been described by other investigators in solutions less acid than those that are useful in microtechnique. The production of blue and various shades of red in tissues stained by solutions containing iron(III) and chromoxane cyanine R probably involves reactions of both the red and the blue complexes of the dye.     

New materials resistant to wear and corrosion to 1000°C

An unusual combination of wear and corrosion resistance has been developed in cobalt and nickel base alloys known as Tribaloy⁷ intermetallic materials. These two-phase alloys depend on the unique properties of a Laves intermetallic phase to resist wear under poor or unlubricated conditions from cryogenic temperatures to about 1000°C. The constituent elements are partitioned so that both the Laves intermetallic and the solid solution phases have generally good resistance to corrosion also. At higher chromium content the corrosion resistance is excellent in most environments.Parts can be fabricated by powder metallurgy, plasma spray coating, casting or hardfacing. Several wear tests are used to demonstrate the qualities of Tribaloy. Wear resistance was excellent at 25°, 315°, 650° and 980°C in air. Another wear test compares several Tribaloy compositions with other commercial, corrosion resistant alloys in 5% hydrochloric acid. Some examples of applications are described.     

基于图像识别技术的总碱度自动测定方法

提出了一种基于图像识别技术的水中总碱度的自动测量方法及装置.以盐酸为滴定剂,溴甲酚绿为指示剂,根据酸碱中和原理,利用等当点时溶液R、G、B值的突跃确定滴定终点,从而测出水中总碱度.实验结果表明,该方法测量碱度的线性范围为0.2～40 mmoL/L,相对标准偏差为0.43％,加标回收率为96.4％～102.6％.用于工业循环冷却水中总碱度的测定,具有操作简便、准确度高的特点,可实现碱度的自动测量.     

赤泥盐酸浸出液中铝的EDTA络合滴定法研究

为了综合利用赤泥,在处理过程中需要准确测定铝的含量。本文考察了乙二胺四乙酸二钠络合滴定法测定赤泥盐酸浸出液中铝的影响程度,结果表明,乳酸加入量应根据待测液中二氧化钛的含量而定,一般加入1＋1的乳酸2 mL能够掩蔽溶液中的二氧化钛;乙二胺四乙酸二钠的加入量以相对于铝过量50%为宜;以二甲酚橙作指示剂,一定要控制溶液pH值,才能使滴定终点敏锐而准确;加热煮沸2~3 min即可使络合反应完全。     

Examination of cell suspensions prepared by cryobiological techniques*

Ultrathin frozen sections have been obtained from single cells both in the fixed and native state. For fixed material a rapid method is described which yields excellent structural preservation. The preparation is based on brief treatment with glutaraldehyde, polyvinylpyrrolidone and ‘encapsulation’ in gelatin. Ultra-thin frozen sections prepared after this technique seem to be especially suitable for cytochemical work. Unfixed testis has been also cut with a dry knife. The contrast in this completely untreated section is sufficient to discern the different parts of spermatozoa.