Technical note on the demonstration of rheumatoid factor by immunofluorescence

The authors present a new technic to point out the rheumatoid factor by immunofluorescence and compare this technic and the others to classical technics of agglutination. This technic allows to avoid the absorption of rheumatoid factor in the serological reactions using the immunofluorescence.     

Technics of measuring the motive force of very small ameboid cells]

A technic have been perfected which measures directly the motive force of very small ameboid cells and indicates the tropism of the amoeba. By using this technic, the motive force of Entamoeba histolytica was measured. It varied between +/- 1.5 x 10-4 dyne. We have also shown chimiotactism in Entamoeba histolytica. The metabolic coumpound excreted by this cell induced negative tropism.     

The Use of the Feulgen Technic with Certain Plant Materials

The Feulgen technic as modified by Heitz promises to become an extremely useful tool in the solution of certain cytological problems. A procedure is outlined for using this technic with root tip smears, and smears of plant microspores. The chief improvement suggested over previous methods is that the material be mounted in euparal, after immersion in 95% alcohol. The technic is of value in the study of chromosome fragmentation, chromatid coiling, centromeres, etc., in both somatic tissue and in microspores.     

A carmine-Giemsa staining technic for meiotic prophase chromosomes of the genus Beta L.

For a detailed study of chromosome morphology in meiotic prophase stages of Beta species, a special double staining technic has been developed. It consists of combined maceration-staining in an ethanol-hydrochloric acid-carmine mixture followed by poststaining of the squashed material in a diluted Giemsa solution. The technic yields well-spread prophase meiotic nuclei showing detailed structures both in weaker stained chromosome segments and in threadlike chromatin structures. This technic proved to be especially favorable for stages which are difficult to interpret, such as pachytene, schizotene and diffuse stages.     

A simple R banding technic.

A simplified R banding technic is described which provides excellent delineation of major regions, easy identification of all chromosomes, and an accurate comparison of homologue lengths. The technic is simple, requiring only an initial incubation in buffer at 85 degrees C followed by acridine orange staining. The best presentation of the R banded chromosomes was obtained by printing in black and white from color transparency film. Variations in the length of the short arms of the acrocentric chromosomes are clearly and consistently defined. Satellites are not demarcated and appear as part of the short arm. Consistent banding was obtained, and the technic is suitable for use in routine clinical cytogenetic work.     

Silica Gel as a Preserving Agent for the Cellular Slime Mold Acrasis rosea

SYNOPSIS. Modifications of the silica gel technic of Perkins and Ogata have been successfully used to preserve Acrasis rosea for 6–13 months and Dictyostelium purpureum for 31 months. The technic is simple, reliable and inexpensive and is recommended for its possible application for the general preservation of certain fungi and protozoa.     

A Carmine-Giemsa Staining Technic For Meiotic Prophase Chromosomes Of The Genus Beta L

For a detailed study of chromosome morphology in meiotic prophase stages of Beta species, a special double staining technic has been developed. It consists of combined maceration-staining in an ethanol-hydrochloric acid-carmine mixture followed by poststaining of the squashed material in a diluted Giemsa solution. The technic yields well-spread prophase meiotic nuclei showing detailed structures both in weaker stained chromosome segments and in threadlike chromatin structures. This technic proved to be especially favorable for stages which are difficult to interpret, such as pachytene, schizotene and diffuse stages.     

Polarized Light Technic A Comparison with the Marchi Method

The authors compare polarized light technic for the study of degeneration of myelinated nerves with the Marchi method. While polarized light shows much the same thing, it has the advantages of being much more rapid, more sensitive, and constant. It does not depend on fixation and staining but on the chemical structure of the myelin substance. These changes in structure begin before the third hour after cutting the nerve of a rat. No further technic is involved beside the making of frozen sections. Photographs are presented to illustrate the method.     

A Flagella Staining Technic for Soil Bacteria

In an attempt to stain the flagella of soil bacteria, many of which have flagella so fine that they are hard to stain by most methods, a technic was developed which combines the best points of Hofer and Wilson's method with that of Bailey as developed by O'Toole. Satisfactory preparations have been obtained for organisms of the genera Pseudomonas, Phytomonas, Alcaligenes, Escherichia, Azotobacter, and Bacillus. This technic, therefore, is recommended as a rapid and constant method for routine flagella staining of all motile aerobic organisms; it combines Hofer and Wilson's method of cleaning the slides with O'Toole's technic of spreading the smears and with a modification of Bailey's mordant.     

Clearing Specimens for the Demonstration of Bone

A brief review is given of some of the older technics of clearing and staining various types of animals, in such a way that the bones are clearly visible in the surrounding tissues. The authors have modified some of these earlier practices. Particularly good results were obtained by combining the Schultze technic with that of Lundvall. Embryos are fixed in 95% alcohol, treated with 1% KOH, stained in 1:10,000 alizarin Red S, cleared in gylcerin, dehydrated with alcohol and further cleared in toluol, toluol saturated with naphthalene, and anise oil saturated with naphthalene. Details of the technic are presented in the text     

The Acetocarmine Smear Technic

The acetocannine smear technic is described primarily for beginners. An effort was made to bring together into one paper the work-a-day details to be followed in collecting specimens and making preparations of plant chromosomes at prophase, of condensed chromosomes at meiosis and mitosis (including mitosis in microspores), and of coiled chromonemata. A schedule for converting temporary slides into permanent mounts is given, and a technic for making smears of the chromosomes in the salivary glands of Drosophila is described.     

Nuclear division in the ameboflagellate Adelphamoeba galeacystis.

Nuclear division is synchronized cultures of the ameoboflagellate Adelphamoeba galecystis has been described. Division in this organism is typically promitotic. It occurs within an intact nuclear membrane and is characterized by the persistence of the nucleolus and its transformation into 2 polar masses. The nucleolus is stained with pyronin-Y by the methyl green pyronin-Y technic, and with Heidenhain's hematoxylin, but is unstained by the Feulgen reaction. The reaction with these stsins is removed after digestion of the nucleolus by ribonuclease. During mitosis the nucleolus undergoes an orderly series of vacuolizations before forming the polar masses. The chromatin is Feulgen positive, stains with methyl green by the methyl green pyronin-Y technic and undergoes a series of characteristic changes during the division process. Synchronizationof amebae grown on coverglasses was accomplished by transfer of cells from 30 to 38.5 C for a period of 100 min. A temporal sequence of nucleolar and chromatin participation in the nuclear division of this organism is suggested.     

The Bodian Technic and the Mosquito Nervous System

Fixation of mosquitoes with Petrunkevitch's para-nitro-phenol fluid with 20 or 25% formalin was found to allow use of Bodian activated protargol technic, where other commonly used fixing fluids yielded no success. Gold toning with subsequent oxalic acid reduction was found to be necessary for Culicid nerve tract preparations.     

Nuclear Division in the Ameboflagellate Adelphamoeba galeacystis

Nuclear division in synchronized cultures of the ameboflagellate Adelphamoeba galeacystis has been described. Division in this organism is typically promitotic. It occurs within an intact nuclear membrane and is characterized by the persistence of the nucleolus and its transformation into 2 polar masses. The nucleolus is stained with pyronin-Y by the methyl green pyronin-Y technic, and with Heidenhain's hematoxylin, but is unstained by the Feulgen reaction. The reaction with these stains is removed after digestion of the nucleolus by ribonuclease. During mitosis the nucleolus undergoes an orderly series of vacuolizations before forming the polar masses. The chromatin is Feulgen positive, stains with methyl green by the methyl green pyronin-Y technic and undergoes a series of characteristic changes during the division process. Synchronization of amebae grown on coverglasses was accomplished by transfer of cells from 30 to 38.5 C for a period of 100 min. A temporal sequence of nucleolar and chromatin participation in the nuclear division of this organism is suggested.     

双向电泳技术进展及在动物和植物科学研究中的应用

综述了双向电泳技术的原理、每一步骤的研究进展及其在动物和植物科学研究中的应用。     

A Chemical and Histochemical study of the Technic for acid Phosphatase

A chemical and histochemical study of Gomori's acid phosphatase technic showed that the causes of its unreliability were: (1) that fixation and other steps of histological procedure inactivate the enzyme to a great extent; (2) the enzyme may diffuse, as demonstrated in frozen sections of acetone-fixed material; and (3) some absorption of lead by the sections takes place. Much of this unreliability is avoided, however, by maintaining as low a temperature as possible during fixation and dehydration, with exposure to the temperature of the paraffin oven for the shortest possible length of time. The relative insolubility and thermo-stability of the enzyme, moreover, indicate the possibility of devising a more satisfactory technic in the future.     

Improvements of Hagmann's Method for Injecting Insect Tracheae

A simple technic for holding and releasing the specimen cage under vacuum by means of paraffin and heat is described. The technic is very easy to follow and greatly facilitates the handling of large numbers of specimens. The specimen cage used is illustrated and the use of a household detergent, Tide, in substitution of Santomerse for preparing Hagmann's solution A is mentioned.     

The Production of Basic Fuchsin Suitable for the Feulgen Technic

Much difficulty has been experienced in obtaining basic fuchsins satisfactory for the Feulgen technic. A method of purification employing sulfur dioxide is described which has been found to improve many unsatisfactory fuchsins. It is also shown that if the best grade of commercial pararosanilin base is used and proper precautions observed in converting it to the chloride or the acetate, a product can be obtained which gives excellent results in the Feulgen technic. The methods by which the base can be converted to the chloride or acetate are described in detail. Precautions are given for avoiding, in the conversion of the base to the dye salts, contamination of the product with the impurities which interfere with the staining. The use of the acetate is recommended because of its greater solubility.     

Manipulation of Tissues for Improved Aceto-Carmine Staining

The importance of the study of the structural-mechanic properties of any particular material in order to improve the technic for aceto-carmine smears and to obtain better preparations of that material has not been, perhaps, sufficiently emphasized in the large number of papers on such cytological technic. The usefulness of such a study will be shown here in two cases met by the writer.