Toluidine Blue-Alizarin Red S Staining of Cartilage and Bone in Whole-Mount Skeletons in Vitro

Cartilage and bone of the developing skeleton can be reliably differentiated in whole-mount preparations with toluidine blue-alizarin red S staining after FAA fixation. The recommended staining procedure is based chiefly on the use of newborn white and Swiss-Webster mice, 4-9 days postnatal, but was tested also on mice and rats 3-8 wk of age. Procedure: Sacrifice, skin, eviscerate, remove body fat, and place specimens in FAA (formalin, 1; acetic acid, 1; 70% alcohol, 8) for approximately 40 min. Stain in 0.06% toluidine blue made in 70% ethyl alcohol for 48 hr at room temperature. Use 20 volumes of stain solution to the estimated volume of the specimen. Destain soft tissues in 35% ethyl alcohol, 20 hr; 50%, 28 hr; and 70%, 8 hr. Counterstain in a freshly prepared 1% aqueous solution of KOH to which is added 2-3 drops of 0.1% alizarin red S per 100 ml of solution. Each day for 3 days, transfer the specimen to a fresh 1% KOH-alizarin mixture, or until the bones have reached the desired intensity of red and soft tissues have cleared. Rinse in water, and place in a 1:1 mixture of glycerol and ethyl alcohol for 1-2 hr, then transfer the specimen to fresh glycerol-alcohol for final clearing and storage. Older mice and rats require procedural modifications: (1) fixation for 2 hr, (2) 0.12% toluidine blue, (3) maceration for 4 days in 3% KOH-alizarin, and (4) preliminary clearing for 24 hr in a mixture of glycerol, 2; 70% ethyl alcohol, 2; and benzyl alcohol, 1 (v/v) before placing in a 1:1 alcohol-glycerol mixture.     

Simultaneous Differential Staining of Cartilage and Bone in Rodent Fetuses: an Alcian Blue and Alizarin Red S Procedure without Glacial Acetic Acid

Differential staining of cartilage and bone has several applications including developmental toxicology studies of new chemical candidates for pharmaceutical, industrial, and environmental use. It has been more common to stain fetal bone only using the dye alizarin red S: however, failure to evaluate the cartilaginous portion of the skeleton may result in the failure to identify toxicologically important alterations in skeletal morphology. Previously, differential staining of fetal cartilage and bone was best achieved by combining alizarin red S for staining bone with alcian blue to stain cartilage in glacial acetic acid solution: however, occupational hazards posed by the use of glacial acetic acid make these methods undesirable. Replacement of the glacial acetic acid with potassium hydrogen phthalate eliminates these hazards without compromising the quality of the stained specimen.     

Rapid Schedules for Koh Clearing and Alizarin Red S Staining of Fetal Rat Bone

Various schedules for staining fetal rat skeleton with alizarin red S were tested to determine a procedure that would produce a completely cleared and well-stained specimen in a short period of time. A 2 day procedure is presented which can produce specimens that are satisfactory but not completely transparent. A 7 day procedure produces cleared and stained specimens which can be well visualized with a dissecting microscope (30×). Fetal rats of 21 days gestation were fixed in 10% formalin for at least 1 wk. The specimens were skinned and eviscerated and then dehydrated in 2 changes of acetone for 12 hr (8 ml per gram body weight). The specimens were then placed in 1% KOM-alizarin red S (6 mg/liter) or 3 days, followed by 10% KOH-alizarin red S for 3 days. Finally, the specimens were placed in a mixture of benzyl alcohol, ethanol, and glycerol (1:2:2) (4 ml per gram body weight) for 12 hr, and then transferred to pure glycerol for storage.     

Iodination-Coupled Tetrazonium and Ferric Ferricya-Nide Reduction Stains for Differentiating Red Blood Cells Containing Fetal or Adult Hemoglobin

Either the iodination-coupled tetrazonium reaction or the ferric ferricyanide reduction procedure can be used to differentiate red blood cells containing fetal hemoglobin (hemoglobin F) from those containing adult hemoglobin (hemoglobin A) in blood smears. Oxalated blood is diluted with 3 parts of physiological saline, and smears are made on slides. The air-dried slides are treated with absolute ethanol for 2 min, dried, and placed in phosphate-citrate buffer of pH 3.2-3.6 for 1 min at 37°C. They are then rinsed in distilled water, and dried for storage or stained at once by either the iodination-coupled tetrazonium or the ferric ferricyanide reduction procedure. Adult hemoglobin is extracted by the buffer, so that red blood cells containing fetal hemoglobin give a much darker stain than those containing adult hemoglobin. The hemoglobin S of patients with sickle-cell anemia behaves like adult hemoglobin.     

A Modification of Alizarin Red S Technic for Demonstrating Bone Formation: Methods of Mounting, Photographing and Demonstrating the Specimens

This paper shows that by using solutions heated in the incubator during certain stages, the alizarin red S method of staining the ossified centers in embryos has been shortened, with a consequent saving in time.

New methods of mounting the specimens have been evolved and are described in detail.

The technic of photographing mounted and unmounted specimens is outlined and illustrated by diagrams.

Diagrammatic illustrations are provided of the various types of apparatus used, including a plan of the cabinet for demonstrating clearly the smaller embryos mounted between watch glasses. Photographic examples of the results achieved are also shown.     

A Modification of Alizarin Red S Technic for Demonstrating Bone Formation: Methods of Mounting,Photographing and Demonstrating the Specimens

This paper shows that by using solutions heated in the incubator during certain stages, the alizarin red S method of staining the ossified centers in embryos has been shortened, with a consequent saving in time.

New methods of mounting the specimens have been evolved and are described in detail.

The technic of photographing mounted and unmounted specimens is outlined and illustrated by diagrams.

Diagrammatic illustrations are provided of the various types of apparatus used, including a plan of the cabinet for demonstrating clearly the smaller embryos mounted between watch glasses. Photographic examples of the results achieved are also shown.     

Alizarin Red S As An Intravital Fluorochrome in Mineralizing Tissues

To avoid interference with weight gain following alizarin red S injections, low doses of an order of 25 mg/kg body weight must be used. Two such doses given 4 days apart to 24-day-old rats produced no visible staining of bone or dentine in undecalcified sections examined by ordinary light microscopy. Under ultraviolet light, however, staining was evident in the form of fine, red fluorescent lines.     

The Demonstration of Bone and Cartilage Remodelling Using Alcian Blue and Hematoxylin

A new staining technique based on alcian blue and hematoxylin was used during the study of experimentally produced fractures in long bone. The distinction between cartilage, woven bone, mature bone and necrotic bone during successive stages of the fracture healing process was particularly remarkable. This method was found also to be very useful in the study of general tissue morphology. It is suggested that this postdecalcification light microscopy staining method is suitable for studies of cartilage and bone development with particular reference to ossification, remodelling and bone pathology.     

Advantages in the Use of Aldehyde Fuchsin with Van Gieson's Picro-Fuchsin Counterstaining for Differentiating Bone and Cartilage

Specimens of bone were fixed in 10% neutral phosphate-buffered formalin or in Bouin's fluid and decalcified in 10% formic acid buffered with 10% sodium citrate. Materials were embedded in paraffin and 4-5 μ sections attached to slides were oxidized with 0.5% KMnO₄, decolorized in 1% oxalic acid, stained with aldehyde fuchsin, and counter-stained with Van Gieson's picro-fuchsin. Sections were dehydrated, cleared and mounted in a synthetic resin. Microscopically, the differentiation between bone and cartilage was seen as red and purple respectively, with connective tissue red; muscle and erythrocytes, yellow; and elastic fibres purple. The areas occupied by bone, cartilage and erythrocytes could be compared, and also the depth to which cartilage extended into the ossified sites. The advantages of this staining combination are: good contrasts in colour, ease of applying the stain, and virtual self-differentiation of the staining solutions.     

Large-scale double-staining of rat fetal skeletons using Alizarin Red S and alcian blue

A critical component in the conduct of a prenatal developmental toxicity study is the evaluation of fetal skeletal development. As the developing rodent fetus is typically evaluated at gestation day 20, at a time when ossification of the skeleton is incomplete, a thorough assessment of skeletal development would include both ossified and cartilaginous structures. Current methods to double-stain the fetal skeleton using Alizarin Red S and Alcian Blue are typically described for small sample sizes or using time allotments for each processing step that are unsuitable for industry. In an industrial setting, there is a need for an effective means to double-stain fetal skeletons on a large scale (i.e., hundreds of fetuses simultaneously). This article describes a method used in our laboratory to stain both fetal bone and cartilage using solutions and procedures on an industrial scale.     

Aldehyde-Fuchsin Followed by Toluidine Blue O for Pancreatic Islet Cells

A number of methods have been devised for the identification of the various cells of the pancreas. Currently, aldehyde-fuchsin (Gomori 1950) is one of the most extensively used stains for the β cells. To show other cells, Gomori suggested superimposing either an orange G or a trichrome stain. In our laboratory, we have been using a basic dye, following aldehyde-fuchsin for β cells, as a buffered solution of toluidine blue O (C.I. No. 52040) for $aL cells. This method is simple and practical, and yields satisfactory and reproducible results.     

Aldehyde-Fuchsin Followed by Toluidine Blue O for Pancreatic Islet Cells

A number of methods have been devised for the identification of the various cells of the pancreas. Currently, aldehyde-fuchsin (Gomori 1950) is one of the most extensively used stains for the β cells. To show other cells, Gomori suggested superimposing either an orange G or a trichrome stain. In our laboratory, we have been using a basic dye, following aldehyde-fuchsin for β cells, as a buffered solution of toluidine blue O (C.I. No. 52040) for $aL cells. This method is simple and practical, and yields satisfactory and reproducible results.     

Dissimilar Staining Properties of Purified and Certified Toluidine Blue

Certified toluidine blue (National Aniline Co.). applied to sections of frog blastulae, stained the nuclei light blue and left the yolk platelets either unstained or light blue. Purified toluidine blue (also National Aniline Co.) stained the nuclei a deep blue and the yolk platelets a brilliant pink with deep blue borders. Some of the observations suggest that this difference in staining behavior is due to the presence of an inhibitor in the certified dye, which suppresses the metachromatic staining of the platelets and reduces the intensity of the nuclear staining. Unsuccessful attempts were made to remove the inhibitor by salting out the certified dye and washing it with alcohol or by extracting it with chloroform. Details of these attempts, and of other experiments designed to identify the stainable substrates in the yolk platelets are given in the text.     

Histological, Chromatographic and Spectrophotometric Studies of Toluidine Blue

Chromatographic analysis of commercial batches of toluidine blue shows these to be dye mixtures. Histologically, some samples were found to be poor metachromatic dyes. These unsatisfactory stains contained blue dyes with little or no metachromatic properties as well as a metachromatic fraction. On the other hand, contaminating dyes in histologically satisfactory samples had poor staining qualities and hence did not interfere with the color produced by the metachromatic fraction.

Chromatographic fractionation of different commercial batches of toluidine blue yielded identical, homogeneous metachromatic dyes. These purified dyes had a peak absorption at 615 mμ in contrast to that of purified azure A whose peak absorption was at 622.5 mμ.     

Permanent Stained Preparations of Synovial Fluid for Detection of Calcium Compounds Using Alizarin Red S

Permanent preparations of air dried synovial fluids were prepared by staining calcium compounds with alizarin red S stain; each slide was coverslipped with Permount. Variables studied were: (a) concentration of the solution of alizarin red S, (b) pH of staining solution, (c) time of incubation in staining solution and aqueous and ethanolic content of staining solution. The staining effect of each solution was tested on calcium pyrophosphate dihydrate, calcium oxalate, apatite and monosodium urate (MSU). Of all the solutions, best results were obtained with 0.25% alizarin red S in 50% ethanol at pH 7.0 for 30 min. With this solution, the calcium-containing compounds were well stained. MSU did not stain and still preserved negative birefringence on polarizaton. Fixation of smears with ethanol served a double purpose: It fixed the slides without dissolving or removing MSU or the calcium compounds, yet it did dissolve five corticosteroids commonly used for intra-articular injection which may interfere with interpretation of compensated polarized light microscopy of synovial fluids.     

A Rapid HCl/Toluidine Blue Squash Technic for Plant Chromosomes

Fresh or pretreated root tips are simultaneously fixed and hydrolysed in 5 N HC1 for 15 min at room temperature. After washing they are macerated on a slide in a drop of 0.05% toluidine blue made up in McIlvaine citric acid-Na₂HPO, buffer at pH 4.0. Pressure on the cover slip completes the squash preparation. It is made permanent by removing the cover slip on dry ice, air drying and mounting in Euparal.     

改良的肥大细胞甲苯胺蓝染色法

目的:本研究旨在运用一种改良的甲苯胺蓝染色方法鉴定体外分离培养的肥大细胞形态,为肥大细胞研究提供简便的检测方法。方法:体外诱导分化培养小鼠骨髓来源的肥大细胞,4周后收集细胞、固定、染色。比较不同固定温度及时间对甲苯胺蓝染色效果的影响,确定最佳条件。结果:SCF和IL-3体外培养诱导出小鼠骨髓来源肥大细胞。肥大细胞用改良的甲苯胺蓝染色后细胞着色效果较好,细胞多呈圆形或椭圆形且胞膜较完整,胞浆中充满大量的紫红色颗粒。结论:本研究成功运用一种适用于体外培养小鼠骨髓源肥大细胞的甲苯胺蓝染色法,并发现肥大细胞在37℃充分固定后进行染色,可以降低肥大细胞发生脱颗粒。此操作方法稳定性好、简便,适用于体外培养的肥大细胞形态学观察。     

The Differentiation of Placoid, Ctenoid and Cycloid Scales by Means of Alizarin Red S

This technic has been used successfully by the author for staining, in situ, the placoid scales of selachians and the smaller forms of cycloid and ctenoid scales of teleosts. Sections of skin are dissected from the ventrum of the specimen, cleaned of fascia and muscle tissue and fixed in a 10% formalin solution. The section is macerated in several changes of a 3% KOH solution until translucent. Staining is accomplished in a fresh 2% KOH solution to which is added a saturated alcoholic solution of alizarin red S. The section remains in the stain for 24 hours. If necessary, the tissue may be quickly destained in acid alcohol (1% H₂SO₄ in 95% alcohol). The skin is dehydrated in cellosolve or the alcohol series and cleared in methyl salicylate. Placoid and teleost scales prepared in this manner are stained a brilliant red. The various parts of the denticle are well differentiated.