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Showing papers in "Biotechnic & Histochemistry in 1955"


Journal ArticleDOI
TL;DR: The red staining of eosinophilic granules and osteoid is readily distinguished by its persistence after ribonuclease or warm-buffer extraction, and it was possible to prepare a differentially staining mixture of either of these pyronins combined with methyl green.
Abstract: Two samples of pyronin Y were found which, with the exception of eosinophilic granules and osteoid, stained only nucleic acids in animal tissues. Good differentiation was obtained. with n-butyl alcohol. It was therefore possible to prepare a differentially staining mixture of either of these pyronins combined with methyl green. This mixture stains polymerized desoxyribose nucleic acid (DNA) clear green, depolymerized DNA and ribonucleic acid red. The red staining of eosinophilic granules and osteoid is readily distinguished by its persistence after ribonuclease or warm-buffer extraction. The staining mixture consists of: (1) pyronin Y (Edward Gurr or G. T. Gurr), CHCl3 extracted, 2% aq, 12.5 ml; (2) methyl green, CHCl3 extracted, 2% aq, 7.5 ml; (3) distilled water, 30 ml. The staining procedure is as follows. (1) Immerse slides 6 min in the dye mixture. (2) Blot with filter paper. (3) Immerse in 2 changes of n-butyl alcohol, 5 min each. (4) Xylene, 5 min. (5) Cedar oil, 5 min. (6) Apply Permount and cover.

189 citations


Journal ArticleDOI
Sandison At1
TL;DR: Tissue from Egyptian mummy material is extremely brittle; hence it was handled in perforated glass tubes during processing, which allowed regular sectioning and staining to be done successfully.
Abstract: Tissue from Egyptian mummy material is extremely brittle; hence it was handled in perforated glass tubes during processing. The first (softening) fluid consisted of 96% ethyl alcohol, 30 vol; 1% aqueous formalin, 50 vol; 5% aqueous Na2CO3, 20 vol. It was used in a fluid to tissue volume ratio of 100:1 and allowed to act overnight. A special dehydrating sequence: 80% alcohol, 3-6 hr; 8% phenol in 96% alcohol, and absolute alcohol followed by 3 changes of amyl acetate, 6-18 hr each; 3 changes of 1 % celloidin in methyl benzoate, 24 hr each; then through benzene and embedding in paraffin completed the special technic. This allowed regular sectioning and staining to be done successfully.

102 citations


Journal ArticleDOI
TL;DR: The new cresyl echt violet acetate, of which three different batches have been tested, proves to be a very useful Nissl stain, especially valuable for formalin-fixed, frozen-sectioned material and also for staining celloidin embedded material.
Abstract: The new cresyl echt violet acetate, of which three different batches have been tested, proves to be a very useful Nissl stain. It is especially valuable for formalin-fixed, frozen-sectioned material. By using a buffered staining bath and controlled timing in dehydration it is possible, on paraffin embedded material, to use these dyes as progressive stains apparently specific for nucleic acids. With a saturated aqueous solution of the dye, especially when a mordant of lithium carbonate is used, it is possible to stain material that has been preserved in formalin for several years and also material from which nucleic acids have been removed. The dye is useful also for staining celloidin embedded material. With the buffered stain proposed, differentiation is much easier than with older methods which included a gross overstaining and a long destaining procedure.

65 citations


Journal ArticleDOI
A. W. H. Braden1
TL;DR: It is concluded, therefore, that the use of the PAS technic for the histochemical demonstration of acid mucopolysaccharides is misleading, for many im...
Abstract: The reaction to three histochemical tests of preparations of hyaluronic acid, chondroitin sulfate, heparin, the acidic mucopolysaccharides from cornea, gastric mucin, and dentine, and also of the neutral mucopolysaccharide from gastric mucin was studied. To 1% aqueous solutions of the acid mucopolysaccharides, equal volumes of 1% casein solution were added; drops of the resulting solutions were placed on slides and dried at 37 °C. The films were then fixed in acetic-alcohol (1:9). The technics employed were the periodic acid-Schiff (PAS) test, the metachromatic reaction and the Hale test. The relative acidity of the preparations was demonstrated by staining in dilute aqueous methylene blue at pH 3-6. With the exception of the preparation from dentine, the acid mucopolysaccharides stained only weakly with PAS; the neutral mucopolysaccharide stained strongly. It is concluded, therefore, that the use of the PAS technic for the histochemical demonstration of acid mucopolysaccharides is misleading, for many im...

65 citations


Journal ArticleDOI
TL;DR: The action of different prefixing agents including water and a dilute CaCl2 solution on plants with high chromosome number showed that all the solutions tried exhibited marked effect on the physical state of the plasma.
Abstract: The action of different prefixing agents including water and a dilute CaCl2 solution on plants with high chromosome number showed that all the solutions tried exhibited marked effect on the physical state of the plasma. Also the plasmatic constitution of the pretreated tissue differed from the appearance of one fixed directly in dye-acid mixture for a few seconds without any pre-treatment. For the clarification of the karyotypes, the best results have been obtained with paradichlorobenzene. It was used as a prefixing agent with a short schedule for temporary smears of difficult materials, particularly those with high chromosome number. The method comprised treatment of the root tips in a saturated aqueous solution of the chemical for 3 hours at 12-16°C., followed by 4-5 seconds heating just to boiling in orcein-hydrochloric acid mixture, then smearing in 1% aceto-orcein solution.

64 citations


Journal ArticleDOI
TL;DR: A new temporary stain for the demonstration of nuclear and cytoplasmic structures in Paramecium and other protozoan ciliates during both vegetative reproduction and meiotic reorganization and results in a delicate and more transparent stain which affords greater clarity of internal structure.
Abstract: A new temporary stain for the demonstration of nuclear and cytoplasmic structures in Paramecium and other protozoan ciliates during both vegetative reproduction and meiotic reorganization consists of a mixture of 10.5 parts of acetocarmine, 4.5 parts of 45% acetic acid, 2 parts of 1 N HCl and 1 part of 1% solution of fast green FCF in 95% alcohol. This stain replaces the acetocarmine and acidified methyl green nuclear stains commonly employed and has the following advantages: (1) it affords simultaneous differential stainability of nucleus and cytoplasm (brown-red and green to grey-green, respectively); (2) it provides differential stainability of newly developing macronuclei (homogeneous pale green), fragments of the old macronucleus (brown-red), and food vacuoles (granular, bright blue-green); and (3) it results in a delicate and more transparent stain which affords greater clarity of internal structure. Proportions may be shifted slightly to achieve the optimum results for any particular organism. Conc...

59 citations


Journal ArticleDOI
TL;DR: A method is described in which sections or smears of animal tissue are covered with stripping film, exposed and developed for autoradiograms, and stained with modified Giemsa through the film.
Abstract: A method is described in which sections or smears of animal tissue are covered with stripping film, exposed and developed for autoradiograms, and stained with modified Giemsa through the film. Results are consistently satisfactory.

46 citations


Journal ArticleDOI
TL;DR: A freeze-dry method where cold absolute ethanol is used as a dehydrating agent in place of vacuum dehydration has been applied to various plant materials with good cytological results.
Abstract: A freeze-dry method where cold absolute ethanol is used as a dehydrating agent in place of vacuum dehydration has been applied to various plant materials with good cytological results. The method involves: (a) freezing rapidly small pieces of tissue 1 cubic mm or less in partly frozen isopentane cooled with liquid nitrogen, (b) transferring quickly to vials of cold absolute ethanol at -41° to -45°C, and (c) holding within this temperature range for 3 days to dissolve the ice. A simply constructed cryostat is used to maintain the vials of absolute alcohol and tissue at the cold temperature. This consists of a semi-frozen constant temperature bath of either 65% ethanol or pure diethyl oxalate in a tightly covered beaker which fits within a large dewar flask half filled with dry ice. The bath is arranged so that it will be on top of and in contact with the dry ice but properly insulated to prevent freezing completely.The resulting dried tissue is very unstable in either water or hot absolute ethanol; therefo...

39 citations


Journal ArticleDOI
TL;DR: A rapid technic for the preparation of 6 μ serial sections of undecalcified bone is described and microscopic structural detail is preserved and there is no evidence of translocation of the radioactivity.
Abstract: A rapid technic for the preparation of 6 μ serial sections of undecalcified bone is described. The specimen is fixed and dehydrated in acetone and ether. It is then treated with a 1:1 mixture of the monomers of ethyl and n-butyl methacrylate catalyzed with benzoyl peroxide. The monomers are removed with ether and the ether is removed under vacuum. Infiltration is accomplished under vacuum using a partial polymer of the same mixture of monomers. Polymerization is completed in 36 hours under pressure at 50°C. The tissue is sectioned with a heavy-duty microtome, the sections are mounted on glass slides and nuclear emulsions applied. Young and adult bone of laboratory animals and man have been cut successfully. Microscopic structural detail is preserved and there is no evidence of translocation of the radioactivity.

36 citations


Journal ArticleDOI
TL;DR: A silver staining method for paraffin sections of material fixed in HgCl2, sat.
Abstract: A silver staining method for paraffin sections of material fixed in HgCl2, sat. aq., with 5% acetic acid is as follows. Process the sections through the usual sequence of reagents, and including I-KI in 70% alcohol, thiosulfate (5% aq.), washing and back to 70% alcohol containing 5% of NH4OH (conc. aq.). After 3 minutes in the ammoniated alcohol, wash through tap water and 2 changes of distilled water and silver 5-10 minutes at 25°C. in 15% AgNO3 aq. to which 0.02 ml. of pyridine per 100 ml. has been added. Blot the slide, but not the section and do not rinse. Reduce at 45°C. in 0.1% pyrogallol in 55% alcohol, then rinse in 55% alcohol and wash in water. The remainder of the process consists of gold toning, intensifying in oxalic acid, fixing in 5% Na2S2O3, washing, dehydrating, clearing and covering. When the specimen contains much smooth muscle, the I-KI solution is acidified before use by adding 2 ml. of 1N nitric acid per 100 ml., and the sections treated for 3 minutes instead of the usual 2 minutes. ...

20 citations


Journal ArticleDOI
TL;DR: Mounted deparaffinized sections were stained for 30–60 minutes at room temperature in a mixture of equal volumes of 0.1% aqueous solutions of safranin O and fast green FCF filtered before use.
Abstract: Mounted deparaffinized sections were stained for 30–60 minutes at room temperature in a mixture of equal volumes of 0.1% aqueous solutions of safranin O and fast green FCF filtered before use. They...

Journal ArticleDOI
TL;DR: An investigation has been carried out on the amount of activity lost from rat and human tissues during fixation and dehydration and various procedures for staining sections before application of photographic emulsion and after developing are discussed.
Abstract: Histological methods suitable for use in autoradiographic technics are described. An investigation has been carried out on the amount of activity lost from rat and human tissues during fixation and dehydration. Losses in the processing fluids varied from 25% to 90% of the initial activity for radioactive phosphorus and 4% to 20% for radioactive iodine in various fixatives.The care necessary in handling sections if distribution of total activity is being studied is emphasized and floating on absolute alcohol is suggested as an alternative to warm mercury. Various procedures for staining sections before application of photographic emulsion and after developing are discussed. Ehrlich's hematoxylin applied regressively has given good results and eosin has been used successfully as a counterstain. Orth's lithium carmine is resistant to photographic developer and also Feulgen's stain counterstained with fast green can be used before covering the slides with photographic emulsion.

Journal ArticleDOI
TL;DR: The addition of the detergent to the Giemsa solution resulted in cleaner preparations and better stained organisms, and Morphological details were more distinct, thus facilitating microscopical detection and identification of species.
Abstract: The effects of a surface active agent, Triton X-100, were studied in the routine Giemsa staining of seven blood parasites: Plasmodium vivax, Trypanosoma cruzi, T. lewisi, Leishmania donovani, Toxoplasma gondii, and microfilariae of Dirofilaria immitis and of Wuchereria bancrofti. Concentrations of Triton X-100 ranging from 0.01% to 0.5% were used in staining (a) both thick and thin blood films of all organisms except L. donovani, (b) tissue smears of L. donovani, and (c) tissue and peritoneal fluid smears of T. gondii. In general, the addition of the detergent to the Giemsa solution resulted in cleaner preparations and better stained organisms. Morphological details were more distinct, thus facilitating microscopical detection and identification of species. The most beneficial concentration of Triton X-100 was found to be 0.1%. Since it has a hemolytic effect on erythrocytes, concentrations above 0.01% cannot be used in staining thin blood films. It is suggested also that the use of Triton-Giemsa may help...

Journal ArticleDOI
TL;DR: A two-solution adhesive, shown to keep for over two years at room temperature, consists of gelatin, calcium propionate, and Roccal and is suitable for hard-to-affix material.
Abstract: A two-solution adhesive, shown to keep for over two years at room temperature, consists of the following: (A) gelatin, 1 g.; calcium propionate, 1 g.; Roccal (10% benzalkonium chloride), 1 ml.; water, 100 ml.: (B) chrome alum (cryst.), 1 g.; water, 90 ml.; formalin, 10 ml. For flooding slides, mix 1 volume of A with 9 of B. Remove excess by blotting and wiping around the edges of sections. The adhesive is suitable for hard-to-affix material.

Journal ArticleDOI
Bowen Cc1
TL;DR: A method is described which yields permanent Feulgen preparations of meiotic material from Lilium anthers, eliminating difficulties heretofore encountered and some applications are suggested.
Abstract: A method is described which yields permanent Feulgen preparations of meiotic material from Lilium anthers, eliminating difficulties heretofore encountered. Cells are handled as a suspension through the staining and fixing procedure, and centrifugation and decantation of the supernatant permits changing reagents. Several technics are given which minimize the optical problems created by the heavily sculptured walls of pollen grains, and some applications are suggested.

Journal ArticleDOI
TL;DR: Deparaffinized insect sections are brought down to water and overstained in a 0.1% solution of azocarmine G in 1% acetic acid until the endocuticle is green, and mounted in Mohr and Wehrle's medium, a mountant of the Euparal type.
Abstract: Deparaffinized insect sections are brought down to water and overstained in a 0.1% solution of azocarmine G in 1% acetic acid. They are then destained in a saturated solution of orange G until the azocarmine G is removed from the endocuticle and the latter is colored pale yellow. After washing, the sections are transferred to a 5.0 % solution of phosphotungstic acid in water for 3 min. They are then rinsed in distilled water and stained in a 0.1% solution of methyl green in 1% acetic acid until the endocuticle is green. Differentiation is done in 2 changes of 95% alcohol. The sections are then dehydrated either in absolute alcohol or dioxane, cleared in a mixture of “camsal”, eucalyptol, dioxane, and paraldehyde (1:2:2:1), and mounted in Mohr and Wehrle's medium, a mountant of the Euparal type.

Journal ArticleDOI
TL;DR: Observation and measurement of fibril angles in increment cores or similar small samples from living pine trees was facilitated by the use of fluorescence microscopy and Photomicrography was feasible also, and the need of preparing microtome sections was obviated.
Abstract: Observation and measurement of fibril angles in increment cores or similar small samples from living pine trees was facilitated by the use of fluorescence microscopy. Although some autofluorescence was present, brighter images could be obtained by staining the specimens with a 0.1% aqueous solution of a fluoro-chrome (Calcozine Ha vine TG extra concentrated, Calcozine red 6G extra, rhodamine 6G, rhodamine 6GD extra, or a succession of flavine and rhodamine). Staining for 2—5 min followed by a 5-10 sec washing in distilled water and drying 15 min at 190-195°C prepared radially split surfaces of specimens for microscopic observation with ultraviolet light. Measurement of fibril angles, important for the determination of wood strength and the properties of its pulp, was made with a protractor eyepiece. Photomicrography was feasible also, and the need of preparing microtome sections was obviated.

Journal ArticleDOI
TL;DR: If, in the procedure of staining nerve fibers in mounted paraffin sections with Protargol according to Bodian, the reduction after toning with gold chloride is executed in a solution of 3–6 drops of aniline oil in 100 ml of 50% alcohol instead of in the prescribed oxalic acid solution, the selectivity of the staining of peripheral nerves is increased.
Abstract: If, in the procedure of staining nerve fibers in mounted paraffin sections with Protargol according to Bodian, the reduction after toning with gold chloride is executed in a solution of 3–6 drops of aniline oil in 100 ml of 50% alcohol instead of in the prescribed oxalic acid solution, the selectivity of the staining of peripheral nerves is increased. This is effected by a reduction in the intensity of the staining of nonnervous tissue elements. However, at the same time the staining of nonnervous tissue is richer in details and consequently more satisfactory from a histological point of view than it is according to the original method of Bodian or the modification of this method by Ziesmer (1951).

Journal ArticleDOI
TL;DR: The sulfhydryl inhibitor N-ethyl maleimide completely inhibited the reduction of 2,3,5-triphenyltetrazolium chloride in meristematic and embryonic vascular tissues of Coleus sp.
Abstract: The sulfhydryl inhibitor N-ethyl maleimide completely inhibited the reduction of 2,3,5-triphenyltetrazolium chloride in meristematic and embryonic vascular tissues of Coleus sp. stems, Ricinus communis root tips, ungerminated Tea mays embryos, and epicotyls and coleoptiles of germinated Tea mays embryos, in a concentration of 200 mg/lit. Inhibition was reversed by the addition of cysteine or reduced glutathione (200 mg/lit) to the inhibitor medium. N-ethyl maleimide was effective also in blocking the nitro-prusside and 1-(4-chIoromercuriphenylazo)-naphthol-2 sulfhydryl staining reactions, but other substituted maleimides were ineffective in inhibiting the tetrazolium reaction in these tissues. Experiments were conducted to determine the histological pattern of sulfhydryl groups as indicated by a modification of the Bennett 1-(4-chloro-mercuriphenylazo)-naphthol-2 test and a modification of the Rap-kine nitroprusside test in certain plant tissues. A positive correlation was observed between tissues reducin...

Journal ArticleDOI
TL;DR: Results indicate that pretreatment of tissues with a proteolytic enzyme, such as pepsin or papain, removes the collagenous elements, and permits a clearer and more accurate identification of the nerves.
Abstract: It is well known that the argyrophilic property of connective tissue elements has been a factor in the unreliability of the various silver-impregnation methods used for nerve study. Their presence may mask the appearance of nerves. An enzymatic-hydrolysis procedure was attempted, to remove these interfering fibers. Blocks and cut sections of heads and jaws of rats and monkeys were incubated in a 1% pepsin solution (pH 1.8-2.0) or 1% papain solution (pH 6.0-6.5) at 37°C for varying periods of time depending upon the size and thickness of the specimen. Both control and experimental sections were then impregnated with Pearson's silver-gelatin method. The results indicate that pretreatment of tissues with a proteolytic enzyme, such as pepsin or papain, removes the collagenous elements, and permits a clearer and more accurate identification of the nerves.

Journal ArticleDOI
TL;DR: A short strip of adhesive transfer cellophane tape is applied to the face of the block to provide backing for the section during cutting and handling, and the adhesive is dissolved from the section in unleaded gasoline.
Abstract: A short strip of adhesive transfer cellophane tape is applied to the face of the block to provide backing for the section during cutting and handling. The tape is sealed to the nuclear track plate ...

Journal ArticleDOI
Karl Esser1
TL;DR: In styles, which contain a conducting tissue, the pollen tubes can be stained with aceto-carmine and so distinguished from the conducting tissue.
Abstract: In styles, which contain a conducting tissue, the pollen tubes can be stained with aceto-carmine and so distinguished from the conducting tissue. Pollinated styles are macerated in a saturated aqueous solution of chloral hydrate. The time of treatment is specific for each kind of style (0.5-24 hr). The stigma, with its conducting tissue, is dissected under a dissecting microscope, placed on a slide, a drop of aceto-carmine added and the preparation covered with a cover slip. By a slight pressure on the cover slip, the conducting tissue is spread out. Aceto-carmine is added from time to time during 24 hr, and the pollen tubes, especially their ends, stain a deep red. The cells of the conducting tissue are only faintly stained. In styles which have a length of only a few millimeters, the pollen tubes can be seen without dissecting the conducting tissue. The preparations can be made relatively permanent by sealing the covers with Kronig'schem Glasskitt (Hollborn und Sohne, Leipzig, Germany).

Journal ArticleDOI
TL;DR: Variations in pH elicited different degrees of stain retention; different fixation altered staining affinity even though staining was effected at identical pH values.
Abstract: The effect of pH on staining by 7 dyes of the eosin group was studied by means of specimens fixed 12-18 hr in Gilson's, in Petrunkewitsch's, or in Zenker's fluids, respectively. Sections were soaked in water or alcohol, depending upon the stain solvent, adjusted in 31 equal steps from pH 4.0 to 10.0 before being stained in similarly adjusted dye solutions. The stained sections were rinsed at H-ion concentrations identical to that at which staining took place, until no further color came away, and mounted. Variations in pH elicited different degrees of stain retention; different fixation altered staining affinity even though staining was effected at identical pH values.

Journal ArticleDOI
TL;DR: Removal of Feulgen-stainable material from the cell nucleus was accomplished by treatment of sections with streptococcal desoxyribonuclease, and control slides showed characteristic nuclear staining.
Abstract: Removal of Feulgen-stainable material from the cell nucleus was accomplished by treatment of sections with streptococcal desoxyribonuclease. The procedure recommended is (1) Deparaffinize with xylene, followed by descending grades of alcohol. (2) Wash in tap water. (3) Treat slides for 1 hour at 37°C. with streptococcal desoxyribonuclease (1000 units/ml.) in 0.025M veronal buffer of pH 7.5 containing 0.003M MgSO4. Treat control slides for an equal length of time at the same temperature. Renew the enzyme approximately every 15 minutes. (4) Wash slides briefly in tap or distilled water. (5) Dehydrate, then coat the sections by dipping in a 1% solution of celloidin in alcohol-ether. (6) Subject the preparations to the Feulgen reaction. Control slides showed characteristic nuclear staining; enzyme treated slides did not stain.

Journal ArticleDOI
TL;DR: Storage under severe tropical conditions and periodical checks by staining Plasmodium cynomolgi smears revealed that staining solutions oxidized 6-7 hr with a final pH of 7.8 gave optimum results, while cooler storage conditions were most favorable.
Abstract: Several samples of J.S.B. stain (Jaswant Singh and Bhattacharjee, 1944) solution 1 (polychrome methylene blue) were prepared with 3-8 hr for dichromate-acid oxidation and addition of varying quantities of Na2HPO4 buffer for pH adjustment. Storage under severe tropical conditions and periodical checks by staining Plasmodium cynomolgi smears revealed that staining solutions oxidized 6-7 hr with a final pH of 7.8 gave optimum results. Some precipitation of azures, due to heat after 5 mo, adversely affected the quality of staining solutions, while cooler storage conditions were most favorable. Spectrophotometric and chromatographic studies indicated that the J.S.B. solution 1 was composed of blue and purple components, corresponding to higher methylene azures with methylene blue and thionin with allied products respectively.

Journal ArticleDOI
TL;DR: Anthers containing actively dividing pollen grains were treated with Carnoy's solution (alcohol, chloroform, acetic acid, 6:3:1) and stained in leuco-basic fuchsin for 15-30 minutes before hydrolysing in bulk in 1 N HCl at 60° C.
Abstract: Anthers containing actively dividing pollen grains were treated 1 hour at 18–20° C. with 0.2% solution of colchicine, washed 1 hour in water, soaked in 0.002 M aqueous solution of 8-oxyquinoline at 10-14° C. for 1 hour, washed in water for 1 hour and then fixed in Carnoy's solution (alcohol, chloroform, acetic acid, 6:3:1) for 6 hours to overnight. They were washed successively in acetic-alcohol (1:1) 10-15 minutes, 70% alcohol 10-15 minutes and in water 30 minutes before hydrolysing them in bulk in 1 N HCl at 60° C. for 10-15 minutes. “Finally, they were stained in leuco-basic fuchsin for 15-30 minutes. Pollen grains were squeezed out of a stained anther in a small drop of egg albumen on a slide and the albumen smeared uniformly on the slide. The slide was dipped successively for a few seconds in glacial acetic acid and 45% acetic acid respectively. The smear was covered by a cover glass in a drop of aceto-carmine and pressed gently between folded filter papers. The cover glass was sealed with paraffin a...

Journal ArticleDOI
TL;DR: The crystal violet nuclear stain was compared with the acid Giemsa and thionin-SO2 stains, and it was found that the three technics revealed nuclear structures which were identical.
Abstract: The crystal violet nuclear stain was compared with the acid Giemsa and thionin-SO2 stains, and it was found that the three technics revealed nuclear structures which were identical. Various methods of fixation and hydrolysis were tested and it was concluded that the crystal violet gave more uniform results if used without fixation or hydrolysis. The effects of these treatments on the other technics are discussed.

Journal ArticleDOI
TL;DR: Bacterial preparations, stained by the DeLamater (1951) method, are mounted in a fluid medium which consists of 75 parts heavy mineral oil and 25 parts alphabromonaphthalene.
Abstract: Bacterial preparations, stained by the DeLamater (1951) method, are mounted in a fluid medium (Jensen, 1921) which consists of 75 parts heavy mineral oil and 25 parts alphabromonaphthalene. In these permanent preparations the bacteria appear to be undistorted and the nuclei can be seen clearly and in detail.

Journal ArticleDOI
TL;DR: None of the special fixatives studied revealed any unusual organization in the bacterial cell or exhibited any advantage over the fixatives now in common use by bacter...
Abstract: An examination of some early methods in bacterial cytology shows that technics for demonstrating the nucleus of the Eubacteriales were available for at least twenty years before the current era of investigation, which began in 1942. Although the bacterial nucleus reacts in many respects like the chromatin elements of higher plants, it shows certain peculiarities in its staining reactions. For example, hematoxylin, methyl green, and several preparations used to stain chromosomes, apparently do not exhibit the same affinity for the bacterial nucleus that they do for chromosomes in higher plants. Not only is the selection of a fixative important in nuclear studies, but also the manner in which the fixation is obtained. For example, when bacteria are fixed and processed in a completely wet state it is generally impossible to stain their nuclei. None of the special fixatives studied revealed any unusual organization in the bacterial cell or exhibited any advantage over the fixatives now in common use by bacter...

Journal ArticleDOI
TL;DR: A 50% solution of cellulose caprate in xylene forms a clear pale yellowish syrupy solution of proper consistency for mounting stained and unstained sections, and Prussian blue is well preserved, cobalt sulfide decolorizes in a month.
Abstract: A 50% solution of cellulose caprate in xylene forms a clear pale yellowish syrupy solution of proper consistency for mounting stained and unstained sections. Cover slips become immovable in 30 minutes and slides do not stick together after one-day drying. The refractive index of the xylene solution is 1.4860, of the dry resin 1.4734, and unstained sections remain easily visible. Most stains are well preserved. Prussian blue is well preserved, cobalt sulfide decolorizes in a month.