Carbol Fuchsin as A Stain for Human Chromosomes

Cells derived from cultures of bone marrow or leucocytes were treated with hypotonic citrate solution, squashed in 45% acetic acid frozen with CO₂ to allow removal of the cover glass without disturbing the smear, and stained by the following schedule: absolute alcohol, 5 min; coat with 0.2% parlodion and air dry; 70% alcohol, 5 min; distilled water, 5 min; stain 2-5 min in a mixture of 45 ml of a 0.3% solution of basic fuchsin in 5% phenol, 6 ml of glacial acetic acid, and 6 ml of 37% formaldehyde. Differentiate and dehydrate in absolute alcohol, clear in xylene and cover. The stain is durable for several weeks if slides are stored in darkness when not in use. Results resemble those obtained by Feulgen or aceto-orcein methods.     

A Basic Fuchsin and Alkalinized Methylene Blue Rapid Stain for Epoxyembedded Tissue

Sections 1 μ thick of epoxy-embedded, OsO₄-fixed tissues were stained with 4% aqueous basic fuchsin at 70 C for 1 min, rinsed well and destained, also at 70 C, for 1 min. A 2% aqueous methylene blue solution, alkalinized to pH 12.5 by mixing 1 N NaOH with the dye on the slide in the proportion of about 2:1, was then allowed to act for 2 min at 23-27 C. The stain was rinsed off the slide, and the preparation air dried before applying a mounting medium and cover glass. The mounting medium consisted of immersion oil sealed with epoxy household cement. Stains had not faded after 1 yr. The method is simple, rapid (total time 4-5 min), and provides sharp contrast between cellular and connective tissue components.     

Gallocyanin as A Nuclear Stain

Gallocyanin has been used successfully as a nuclear stain. Sections are cut by the freezing method of either fixed or unfixed tissue. The tissues are warmed (not exceeding 70°C.) for 2-4 minutes in the gallocyanin solution. A counterstain may be used if desired. The most effective are Biebrich scarlet, phloxine, or eosin Y. The sections are then dehydrated and mounted in clarite. The nuclear pattern is clearly demonstrated and the sections are permanent.     

Basic Fuchsin and Picro-Indigo Carmine: A Selective Stain for Cells in Mitosis and for Autoradiography

Selective staining of dividing nuclei is accomplished as follows: paraffin sections, after hydration, are stained 15 min in a saturated aqueous solution of basic fuchsin, washed, then stained 1.5 min in an equal-volumes mixture of indigo carmine saturated in 70% alcohol, and saturated aqueous picric acid. Removal of excess dye with 3 changes of 70% alcohol, dehydration, clearing and covering in a resinous medium completes the process. Nuclei of dividing cells are stained red; cytoplasm and interphase nuclei, light green. This method has been used successfully for determining the mitotic activity of skin, kidney, liver and other rabbit and mouse tissues. Tissue sections previously prepared as autoradiographs may be stained by this method to facilitate the determination of radioactive labeling of mitotic cells.     

A Simple Methylene Blue-Azure Ii-Basic Fuchsin Stain for Epoxy-Embedded Tissue Sections

One micron-thick sections of tissues fixed in glutaraldehyde, or in glutaraldehyde followed by osmium tetroxide, and embedded in a variety of plastic resins were stained in a methylene blue-azure II solution at 65 C, then counterstained in 0.05% basic fuchsin in 2.5% ethanol at room temperature (24 C). Considerable variation was found in methylene blue-azure II staining times for different embedding media. Aged Epon-812 required less staining time than freshly polymerized blocks of Epon-812. The procedure is a simple, rapid staining technique suitable for photomicrography and tissue orientation for electron microscopy.     

Basic Fuchsin as an Indicator in Endo's Medium

The writer has made an investigation of various samples of basic fuchsin for use in the Endo medium for differentiating the bacteria of the colon-typhoid group. Various different concentrations of the fuchsin samples have been used in making the media. The conclusions are as follows:

American made fuchsins differ markedly in their alcohol solubility properties. They contain materials which are very readily soluble in 95% alcohol, but which are precipitated by sodium sulphite.

This precipitation may be prevented by increasing the dilution of the fuchsin in alcohol.

In order to secure more dependable results in the use of decolorized basic fuchsin as an indicator in Endo Agar, it is advisable to test the fuchsin in different dilutions in alcohol in order to secure a completely decolorized solution. It is also advisable to carefully test those fuchsins which decolorize only in high dilutions with a known organism in Endo agar before relying on it as a satisfactory indicator for the presence of sewage organisms.     

DAPI as a Useful Stain for Nuclear Quantitation

A simple-to-use fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI), visualizes nuclear DNA in both living and fixed cells. DAPI staining was used to determine the number of nuclei and to assess gross cell morphology. Following light microscopic analyses, the stained cells were processed for electron microscopy. Cells stained with DAPI showed no ultrastructural changes compared to the appearance of cells not stained with DAPI. DAPI staining allows multiple use of cells eliminating the need for duplicate samples.     

DAPI as a Useful Stain for Nuclear Quantitation

A simple-to-use fluorescent stain, 4′,6-diamidino-2-phenylindole (DAPI), visualizes nuclear DNA in both living and fixed cells. DAPI staining was used to determine the number of nuclei and to assess gross cell morphology. Following light microscopic analyses, the stained cells were processed for electron microscopy. Cells stained with DAPI showed no ultrastructural changes compared to the appearance of cells not stained with DAPI. DAPI staining allows multiple use of cells eliminating the need for duplicate samples.     

Crystal Violet as A Nuclear Stain for Gaffkya Tetragena and Other Bacteria

A method is given to stain the nucleus of Gaffkya tetragena and other bacteria. Only water solutions of crystal violet, mercuric chloride, and nigrosin are used. While the application of heat (50°C. for 20 seconds) is not absolutely necessary, it facilitates the decolorizing process. Some of the nuclei of cells from old cultures were found in various stages of division. The nucleus of a mature cell divides, and each daughter nucleus undergoes a second division usually in a plane at right angles to that of the first division. The nuclear division indicates cell development in units of four cells each. The method was found reliable for demonstrating the nucleus at various periods and stages of growth.     

Preparation and Use of Aldehyde Fuchsin Stain in the Dry Form

A three-day old aldehyde fuchsin staining solution (Gomori, 1950) was precipitated in a separatory funnel by adding 50 ml. of chloroform and 200 ml. of distilled water to each 100 ml. of the staining solution. The mixture was shaken, allowed to settle and the precipitate-bearing layer filtered through paper. The precipitate was dried at 50°C, scraped from the paper and stored in a stoppered vial. To use, 0.5 g. of the dry stain was dissolved in 100 ml. of 70% ethanol containing 1 ml. of concentrated hydrochloric acid. In the dry form, the dye has retained its property of staining thyrotroph cells and neurosecretory substance in the hypophysis of the rat for several months.     

Basic Fuchsin for Staining Vascular Bundles

The following procedure has been found helpful in tracing the vascular supply of succulent plants, such as the garden pea, Pisum sativum. It has been used as a supplementary means of study only, to microscopic slides cut serially thru the plant.     

Basic Fuchsin for Staining Vascular Bundles

The following procedure has been found helpful in tracing the vascular supply of succulent plants, such as the garden pea, Pisum sativum. It has been used as a supplementary means of study only, to microscopic slides cut serially thru the plant.     

A Consideration of French's Test of Basic Fuchsin for Endo's Medium

In describing a method of testing for the return of color in decolorized fuchsin for use in Endo Medium, French states that variations in hydrogen ion concentration fail to influence the appearance of color in this medium.

Duplications of this test were made using alcoholic and aqueous solutions of fuchsin and both sodium sulfite and sodium bisulfite as decolorizing agents.

In the decolorized alcoholic solutions of fuchsin the color failed to reappear when formalin was added, but a small amount of a weak solution of lactic acid caused the color to return.

Alcoholic solutions of fuchsin failed to decolorize in sodium bisulfite solutions until a few drops of NaOH were added. The color, then, reappeared immediately.

Solutions of peptones to which fuchsin had been added were substituted for the original fuchsin solution. Alcoholic and aqueous solutions of fuchsin were added to equal amounts of a 1% peptone solution. The peptone solutions varied in their hydrogen ion concentration and the results showed that those which were neutral decolorized readily while the more acid solutions were but partially decolorized.

Fuchsin decolorized according to results found in this test, was not satisfactory in the Endo medium, especially in the case of the aqueous solutions of fuchsin.

Experiments which were carried on by other workers and checked with this method all indicated that some acid is necessary to secure the restoration of color.     

Basic Fuchsin in Acid Alcohol: A Simplified Alternative to Schiff Reagent

The use of Schiff reagent to demonstrate polysaccharides (after prior periodic oxidation) and nucleic acids (after prior acid hydrolysis) is unnecessary since the same results are obtained by substituting a 20 min staining in a 0.5% w/v solution of basic fuchsin in acid alcohol (ethanol-water-concentrated HC1, 80:20:1) followed by a rinse in alcohol. The shade of the basic fuchsin staining is a little yellower than that achieved with Schiff reagent but the selectivity, light fastness, response to different fixatives, and to prior histo-chemical blocking of the tissue section were much the same for the two methods. The need for prior oxidation or hydrolysis and the inhibitory effect of aldehyde blocking techniques indicate that basic fuchsin, like Schiff reagent, reacts with aldehyde groups. Infrared studies indicate that for cellulose the reaction product is an azomethine.     

Wright's as A Differential Spore Stain

A method of differential spore staining utilizing Wright's stain diluted one to five in a phosphate buffer solution of pH 7.6 and following the general technic of the Dorner method is outlined. Spores are stained a deep blue while the cytoplasm of the sporangium is stained a pinkish red.     

The Cationic Chelate of Chromium and Aluminon as a Selective Nuclear Stain

The chelate k prepared by adding 4.5 gm of aluminon and 100 gm of chrome alum to 200 ml of distilled water, boiling gently for 20 min., filtering, and allowing the filtrate to drop into 3.5 liters of absolute alcohol. The alcoholic suspension is filtered and its precipitate is dried at room temperature. To prepare the staining solution 3 gm of chelate are dissolved in 100 ml of 3% HCI. Hydrated sections—paraffin, frozen, or celloidin—are stained for 30 min to 18 hr at room temperature. The stain is self-limiting and requires no differentiation. Since the stain is not removed by alcohol or weak acids, a large variety of counterstains my be used.     

Wright's as A Differential Spore Stain

A method of differential spore staining utilizing Wright's stain diluted one to five in a phosphate buffer solution of pH 7.6 and following the general technic of the Dorner method is outlined. Spores are stained a deep blue while the cytoplasm of the sporangium is stained a pinkish red.