Histochemical Aspects of the Affinity of Mast Cell Granules for Night Blue

The affinity of mast cell granules for night blue was studied in fresh and fixed rat lip, dog mast cell tumor, normal human ileum, and human mast cell and carcinoid tumors. Fixatives used were 10% formalin, 1% trichloracetic acid in absolute alcohol, and Zenker's and Bouin's fluids. Extractions of fresh tissue with hot water, acids, and bases removed the stainable material or prevented staining, but similar treatment of fixed tissue did not. Hot pyridine was without effect as was chloroform-methanol, but methylation blocked mast cell staining by night blue. Chromic acid oxidation and prolonged Zenker and Bouin fixation also prevented staining. Hyaluronidase treatment was without effect. Sulfhydryl and disulfide linkages were changed without altering the stainability.     

Physical and chemical characteristics of the Blue Nile and the White Nile at Khartoum

Fortnightly measurements of physical and chemical variables were made at two locations on the Blue and White Niles near Khartoum from August 1968 to December 1970. Variables analysed from each river were: temperature, pH, total residue, current velocity, oxygen, alkalinity, phosphate, nitrate, ammonia, silica, sulphate, iron, calcium, magnesium, sodium, potassium and oxidizable organic matter. The seasonal variations of these factors in the two Niles are compared and the interrelationships existing between some of them are discussed. Comparisons with earlier studies on the Nile and with some tropical rivers are made.In the Blue Nile, the amounts of suspended matter and nutrients are largely dependent upon the flood regime. Nitrate, phosphate, iron, oxidizable organic matter and total residue increase considerably in the Blue Nile when the river is in flood (peaks: 1 880 µg NO₃-N l^–1; 0.31 mg Fe l^–1; 3 842 mg total residue · l^–1).In the White Nile, concentrations of nitrate, phosphate, iron, oxidizable organic matter and total residue attain their peaks during the rainy season (270 µg NO₃-N l^–1; 163 tag PO₄-P l^–1; 0.46 mg Fe · l^–1; 502 mg total residue · l^–1).In both rivers, alkalinity, calcium, sodium and potassium tend to increase during the dry season while declining in the rainy season. Silica is depleted at certain times of the year, yet relatively high concentrations are maintained throughout the year and were not expected to limit growth of diatoms. Fall in silica concentrations, unlike nitrate, phosphate and iron, was always followed by a rapid restoration of a high level. Silica and magnesium showed no response to changes in discharge rates.     

A Nile Blue Staining Technic for the Differentiation of Melanin and Lipofuscins

When paraffin sections are stained in 0.05-.01% Nile blue in 1 % sulfuric acid, washed thoroughly in water and mounted in aqueous media, lipofuscins color deep blue, melanins dark green, myelin and red cells lighter greens and background pale green. If, immediately after staining, the preparations are at once extracted with acetone with or without a 1% sulfuric acid rinse, melanins remain dark green, mast cells color purple, lipofuscins and background decolorize and nuclei may stain light green.     

A Nile Blue Staining Technic for the Differentiation of Melanin and Lipofuscins

When paraffin sections are stained in 0.05-.01% Nile blue in 1 % sulfuric acid, washed thoroughly in water and mounted in aqueous media, lipofuscins color deep blue, melanins dark green, myelin and red cells lighter greens and background pale green. If, immediately after staining, the preparations are at once extracted with acetone with or without a 1% sulfuric acid rinse, melanins remain dark green, mast cells color purple, lipofuscins and background decolorize and nuclei may stain light green.     

Histochemical demonstration of hyaluronic acid molecules by Alcian Blue

Summary Specimens of vitreous humour (monkey eye), Wharton jelly (human umbilical cord) and commercial hyaluronates were immersed in buffered fixative solutions containing either aldehydes and Alcian Blue, or aldehydes and Alcian Blue with MgCl₂ as electrolyte. Two MgCl₂ concentrations were used, 0.025m and 0.3m. Immersion in both solutions induced formation of precipitates which were postfixed in OsO₄, dehydrated and embedded for thin section electron microscopy. The use of the same fixative solution produced morphologically comparable precipitates from all three materials. The precipitates, especially after fixation in the presence of electrolyte, were composed of linear, unbranched filaments, frequently aggregated into bundles. The filaments were considered to be molecules of hyaluronic acid.Part of this work was presented at the 10th Meeting of the European Club for Ophthalmic Fine Structure, Copenhagen, September 3–4, 1982.     

An Evaluation of the Nile Blue Test for Differentiating Rhizobia from Agrobacteria

The ability of agrobacteria to reduce Nile Blue more strongly than do rhizobia is the basis of a test for separating these two groups (Hamdi 1969). In a modified test using only 35 parts 10° of Nile Blue in the medium, 89 of 90 rhizobia ( Rhizobium japonicum, R. leguminosarum, R. lupini, R. phaseoli, R. trifolii , cowpea, groundnut and Lotus rhizobia) failed to reduce the dye whereas all 24 strains of agrobacteria ( Agrobacterium radiobacter var. radiobacter, A. r. var. tumefaciens and A. r. var. rhizogenes ) reduced it to the colourless state. Only one Rhizobium strain formed 3-ketolactose from lactose, but 13 agrobacteria produced it. Rhizobium meliloti strains (12) gave variable reactions in both tests. The Nile Blue Test detected rapidly, but not slowly growing, strains of agrobacteria present as contaminants of rhizobia cultures even when their initial numbers were small.     

An Improved Arginine Histochemical Method

An improved arginine histochemical method is described. Development of the color at ice-bath temperature and other modifications produce more color. Uniformity of color development is obtained by transferring the slides quickly so that one solution does not drain from the slide before immersion in the next solution. Clearer sections are obtained by using a tetraethylammonium hydroxide solution to wash out the inorganic alkali, which is potassium hydroxide in the improved method. More stability of color is obtained by mixing tetraethylammonium hydroxide with the mounting medium.     

Luxol Fast Blue Arn: A New Solvent Azo Dye with Improved Staining Qualities for Myelin and Phospholipids

Luxol fast blue ARN (Du Pont, C.I. solvent blue 37) is a diarylguanidine salt of a sulfonated azo dye. This dye was compared with other Luxol blue and Luxol black dyes. Luxol fast blue ARN has improved staining qualities for phospholipids and myelin, and can advantageously be substituted for Luxol fast blue MBS (MBSN). Appropriate staining times for a 0.1% dye solution in 95% ethanol (containing 0.02% acetic add) at 35°-40° C range from 2-3 hr. After staining, the sections should be rinsed in 95% ethanol, rinsed in distilled water, and differentiated for 2 sec in 0.005% Li₂CO₃, rinsed in 70% ethanol, washed in water, and counterstained as required. Phospholipids and myelin selectively stain deep blue. A fixative containing CaCl₂, 1%; cetyltrimethylammonium bromide, 0.5%; and formaldehyde, 10%, in water gave excellent results with brain. However, 10% formalin can be used. The staining of the phospholipids is probably due to the formation of dye-phospholipid complexes.     

Chromatographic Separation and Photometric Analysis of the Components of Nile Blue Sulphate

Samples of Nile blue sulphate (Geigy and G. T. Gurr) were separated by silicic acid thin layer chromatography. The blue sulphated oxazine base was found to consist of 3 components with identical absorption spectra in the visible range. These probably represent isomeric forms of the dye. The red oxazone travelled as a single component. At least 6 minor constituents, present in small amount, were identified. Spectrophotometric examination showed that the sulphated oxazine base has 3 absorption maxima. The absorption spectrum is influenced by pH, dye concentration, dye solvent, and physical state. The absorption spectra of the oxazone and free oxazine base were also measured. These showed marked solvatochromic effects, absorption maxima moving to shorter wavelengths with decreasing solvent polarity.     

A Histochemical Method for the Demonstration of Diphosphopyridine Nucleotide Diaphorase

The present investigation concerning the histochemical demonstration of DPN diaphorase follows the development of a new reagent, Nitro-BT, which has already been used successfully for the cytochemical localization of the succinic dehydrogenase system. The most consistently favorable results were obtained with the lactate-lactic dehydrogenase system buffered at pH 7.4. Using sections of rat kidney and stomach, it was found that the intensity of stain was optimal after 15 minutes incubation at 37°C., conducted aerobically. By appropriate variations in the substrate mixture it was possible to selectively demonstrate the histochemical distribution of certain DPN-linked dehydrogenases in addition to DPN diaphorase. This was made possible by the special distribution of some of these dehydrogenases which distinguished them from one another. Of the dehydrogenases studied the distribution pattern of β-hydroxybutyric dehydrogenase was the most singular. In the gastric mucosa β-hydroxybutyric dehydrogenase was restricted to the cells of the mucous lining epithelium and the gland necks; and in the kidney the enzyme was limited to the cells of the proximal convoluted tubule and thick limbs of Henle's loop. In contrast, lactic dehydrogenase like DPN diaphorase was demonstrable in almost all cytologic elements of both the stomach and the kidney.     

Seasonal fluctuations in the riverain invertebrate fauna of the Blue Nile near Khartoum

The physical conditions on the Blue Nile Bank near Khartoum and the seasonal succession of the invertebrate fauna are described. The fauna is dominated by beetles, mainly Carabidae, in the rainy season which coincides with the annual flood and by spiders, mainly Lycosidae, in the dry season. Climatically, the habitat is relatively mild and food is relatively abundant. The main problem with which the fauna has to contend is the annual rise and fall of the Nile.     

Histochemical Method for Detecting Nitric Oxide Synthase Activity in Cell Cultures

NADPH diaphorase histochemistry has been used extensively for detecting nitric oxide synthase (NOS) activity in various cell types including neuronal cell bodies, vascular endothelium, cells of the immune system and epithelial cells. The use of the diaphorase technique in cell cultures to study the induction of NOS has not been investigated. In this paper we report the use of diaphorase histochemistry as a good marker for the detection of NOS activity in cultured cells. This technique can be used in conjunction with other established techniques to determine the presence and activity of NOS in cultured cells.     

A Method for the Histochemical Differentiation of Cholesterol and Its Esters

Free cholesterol is demonstrated in formalin-fixed frozen sections when treated successively by digitonin, alcohol-ether, and the Schultz technique, in which circumstances cholesterol esters are not visualized. Cholesterol esters and free cholesterol are both demonstrated in comparable sections treated by the Schultz method alone, so that the difference between such sections indicates the sites at which cholesterol esters may be considered present.     

An Embedding Method for Histochemical Studies of Undecalcified Skeletal Growth Plate

We have used glycol methacrylate to study undecalcified skeletal growth plate and subchondral bone. Minor modifications of the original technique including dehydration in glycol methacrylate vacuum infiltration and polymerization in the cold make it quite suitable for embedding of such tissues. Moreover, specimens can be processed quickly and the morphologic and biochemical integrity of the tissue retained so that histochemical procedures can be readily applied. Collagen, glycosaminoglycan, glycogen, lipid, calcium and the activity of alkaline and acid phosphatase were localized. This technique appears to be very useful for studying skeletal tissues.     

A study on diapause of zooplankton in a tropical river - The Blue Nile

SUMMARY. The zooplankton of the Blue Nile overcomes the adverse conditions of the flood by entering into a state of diapause. Resting stages were found in the river bottom, flowing water and rain pools. They were blown to different localities by wind and can withstand long periods of desiccation. Some species of zooplankton go into diapause more than once a year, notably during their seasonal peaks of abundance. Release from diapause occurred in the temperature range 20–30°C and was facilitated by longer photoperiods and decreased concentrations of suspended silt. Various species of zooplankton were induced in facultative diapause when stored in complete darkness.     

尼罗蓝在筛选PHB高产菌株中的应用研究

建立一种简便、高效、可靠的初筛方法是PHB高产菌株筛选的关键。以芽孢杆菌(BacillusP-9)为试验材料,对各种PHB产生菌筛选方法进行了比较,最终确定尼罗蓝染色法为一种最佳方法。并且对试验程序进行了优化,确定尼罗蓝染液的最佳浓度为0.225mg/L,菌株的最佳染色时间为培养后96h。进一步证实了尼罗蓝染色法为一种值得推广的PHB产生菌初筛方法。     

A Simplified Method for Staining Mast Cells with Astra Blue

The copper phthalocyanin dye astra blue has been used to stain differentially mast cells of the intestine; however, the procedure has not been used widely because of the difficulty in preparing and using the dye solution. Described here is a simple, reliable, and consistent method for selectively staining mast cells using a dye solution that may be prepared in any laboratory without the aid of sophisticated pH metering equipment. Astra blue is mixed with an alcoholic solution containing MgCl₂ · 6H₂O and the pH indicator pararosaniline hydrochloride. Concentrated hydrochloric acid is added dropwise, changing the dye mixture from purple to violet and then to blue. In this low range the weakly ionizing ethanol provides a more stable hydrogen ion concentration than the corresponding aqueous solutions used previously. Alcoholic acid fuchsin is a convenient counterstain, and this simple procedure then provides good contrast between the blue staining mast cell granules and the red tissue background.     

An Arginine Histochemical Method Using Sakaguchi's New Reagent

A mounted paraffin section of material fixed in Bouin's, Carnoy's or 10% formalin is allowed to stand 15 minutes at room temperature in a 0.3% solution of 8-hydroxyquinoline in 30% ethanol. The slide, with adhering solution, is placed in 0.15 N hypochlorite (with enough KOH added to make the solution 0.015 N KOH) for 60 seconds, then (without draining) into a solution containing: 10 ml. of 0.15 N KOH; 15 g. of urea; 70 ml. of tertiary butyl alcohol, and water to make 100 ml. Here it is gently agitated for 10 sec. and then kept in a second change of the same solution for 2 min. Two changes of pure tertiary butyl alcohol, 10 sec. and 4 min.; one in aniline, 3 min.; and one of 10 sec. in xylene, complete the procedure. Permount containing 0.02% aniline is used as a mounting medium.     

A Rapid Method for Sectioning Whole Mature Coniferous Seeds for Histological and Histochemical Study

A method is given for rapidly sectioning whole mature conifer seeds. The procedure consists of soaking seeds in water and allowing the seed contents to swell, whereupon the seeds are sectioned in a cryostat. Sections thus prepared are suitable for histological and histochemical staining.     

A Method for Preparing Whole-Body Sections Suitable for Autoradiographic, Histological and Histochemical Studies

A method for the preparation of whole-body sections suitable for autoradiographic and histochemical study is described. Radioactive calcium chloride or [¹⁴Clproline was injected into the abdominal cavity of a rat. Thirty-five minutes after injection of calcium chloride or 40 min after injection of proline the rat was frozen in a mixture of hexane and solid carbon dioxide and blocked in 5% sodium carboxymethyl Cellulose. The carboxymethyl cellulose block was trimmed and a piece of copy paper was attached to the surface of the block with cellulose tape. Cryotome sections cut from the block were transferred from the paper to a glass slide coated with synthetic rubber adhesive. For wholebody autoradiography, sections were freeze-dried for 2 days and then placed against X-ray film. For light microscopic autoradiography, the freeze-dried sections were covered with a dried film of photographic emulsion. For histochemical use, the sections were fixed by raising the temperature to 4 C after immersion in 100% ethanol below -10 C. For histological observation, sections were postfixed with 2.5% glutaraldehyde and stained. Wholebody and light microscopic antoradiographs showed that sections so prepared could be used for the demonstration of soluble substances in wholebody sections and for detailed autoradiography at the light microscopic level, and the stained sections could be used for histological and histochemical studies.