Electron Microscopic Observations of Purified Oat Phytochrome

1971 ◽  
Vol 29 ◽  
pp. 362-363
Author(s):  
J. T. Stasny ◽  
F. E. Mumford
Keyword(s):  
Electron Microscopy ◽  
Ammonium Sulphate ◽  
Microscopic Examination ◽  
Protein Concentration ◽  
Electron Microscopic Examination ◽  
Distilled Water ◽  
Phytochrome A ◽  
Electron Microscopic ◽  
Isolation And Purification ◽  
Molecular Dimensions

The following describes the gross morphology of purified oat phytochrome, as examined by negative staining for electron microscopy. Phytochrome, a chromoprotein important in plant photomorphogenesis, has two photoconvertible forms: PR, absorbing maximally at 664 nm and PFR at 724 nm. Although the isolation and purification of this photoreceptor has been achieved in several laboratories, its molecular dimensions have not been adequately characterized.Phytochrome was extracted from etiolated oat seedlings and purified by a previously published method. The purified oat phytochrome was prepared for electron microscopic examination by precipitation at 50 percent saturation with ammonium sulphate, followed by centrifugation at 30,000xg for 20 minutes. The resulting pellet was dissolved in twice-distilled water to give a protein concentration of approximately 200 ug/ml and then dialyzed against 1000X its volume of distilled water for 18 hours at 4°C.

Poly(ADP-ribosyl)ation of chromatin: kinetics of relaxation and its effect on chromatin solubility

1985 ◽  
Vol 63 (7) ◽  
pp. 764-773 ◽  
Author(s):  
André Frechette ◽  
Ann Huletsky ◽  
Rémy J. Aubin ◽  
Gilbert de Murcia ◽  
Paul Mandel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Enzyme Activity ◽  
Chromatin Structure ◽  
Microscopic Examination ◽  
Electron Microscopic Examination ◽  
Histone H1 ◽  
Electrophoretic Separation ◽  
Electron Microscopic ◽  
Kinetics Of ◽  
Modified Forms

We have studied the kinetics of relaxation of poly(ADP-ribosyl)ated polynucleosomes produced by endogenous enzyme activity by comparing the generation of hyper(ADP-ribosyl)ated histone H1 and its effect on the chromatin structure as revealed by electron microscopy. A correlation can be established between the appearance of histone H1 modified forms and the localized relaxation of the chromatin. We have also noticed, in parallel, that poly(ADP-ribosyl)ated chromatin showed increased solubility in the presence of Mg2+ and 0.2 M NaCl. Electron microscopic examination of the solubilized chromatin produced by poly(ADP-ribosyl)ation shows polynucleosomes exhibiting more relaxed conformation, whereas an increasing amount of hyper(ADP-ribosyl)ated histone H1 is found in the pellet, as shown by acid–urea–polyacrylamide electrophoretic separation of histone extracts.

Unique method of tissue culture preparation for EM

1992 ◽  
Vol 50 (1) ◽  
pp. 728-729
Author(s):  
Fen Wang ◽  
Lindsay B. Ledford ◽  
Jonathan F. Head ◽  
Robert L. Elliott
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Cell Growth ◽  
Crystal Violet ◽  
Microscopic Examination ◽  
Culture Medium ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Unique Method ◽  
Mcf 7

A simplified technique of growing monolayer cells for electron microscopic examination has been developed. Our procedure has eliminated many difficult steps and therefore is easier than those reported by others.Regular Beem capsules for routine embedding for electron microscopy were used(Fig. 1). Prior to tissue inoculation capsules were washed with 5% HCl and gas sterilized. A 0.5 ml cell suspension of MCF-7 cells (10,000/ml) was placed in the capsules and cells settled in the pyramid portion (Fig. 2). Culture medium was alpha-MEM with 10% FCS. Capsules were incubated at 37°C for 3 days. They were then fixed in 70% ethanol for 20 minutes and stained with crystal violet. The pyramid portion of the capsule was cut off and monolayer cell growth was confirmed by examination under a microscope (Fig. 3).

A TECHNIQUE FOR LIGHT AND ELECTRON MICROSCOPY OF THE SYNAPTONEMAL COMPLEX OF THE MOUSE OOCYTE

1982 ◽  
Vol 24 (6) ◽  
pp. 675-680 ◽  
Author(s):  
Weng Kong Sung ◽  
Georgiana Jagiello
Keyword(s):  
Electron Microscopy ◽  
Synaptonemal Complex ◽  
Microscopic Examination ◽  
Light And Electron Microscopy ◽  
Electron Microscopic Examination ◽  
Mouse Oocyte ◽  
Electron Microscopic ◽  
Synaptonemal Complexes

A method is described for obtaining synaptonemal complex preparations from mouse pachytene oocytes for light and electron microscopic examination. A karyotype based on the whole complement of synaptonemal complexes of a pachytene oocyte as visualized by electron microscopy is presented.

Electron microscopic examination of effects of bogma raki and walnut on cochlea

2014 ◽  
Vol 34 (3) ◽  
pp. 266-271 ◽  
Author(s):  
C Cevik ◽  
GS Ozler ◽  
C Arli ◽  
I Tatar ◽  
MF Sargon ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drinking Water ◽  
Microscopic Examination ◽  
Spiral Ganglion ◽  
Organ Of Corti ◽  
Electron Microscopic Examination ◽  
Albino Rats ◽  
Electron Microscopic ◽  
En Bloc ◽  
Hearing Ability

Illegal alcohol beverages known as bogma raki in our country are consumed widely in our region. The studies investigating the relationship between alcohol consumption and hearing ability report different results. In this study, we aimed to investigate the toxic effects of bogma raki that contains neurotoxic substances on cochlea by electron microscopy. To the best of our knowledge, this study is the first in the literature. A total of 48 Wistar male albino rats (aged 12–16 weeks and weighing 200–240 g) were used in the study. The rats were divided into 4 groups with 12 animals in each group. The groups include control, bogma raki, walnut, and walnut + bogma raki groups. Bogma raki (30% v/v, 9.2 ml kg−1 day−1) is added to drinking water of rats in bogma raki group ( n = 12) for 4 weeks. Walnut group rats ( n = 12) are fed with standard rat food and walnut without limitation (10 g kg−1 day−1). Bogma raki + walnut group rats ( n = 12) are fed with standard rat food and walnut and bogma raki is added to drinking water. The cochleas were dissected and removed en bloc and examined by electron microscopy. Perineuronal oedema around neurons of spiral ganglion and hairy cells of organ of Corti were present in the bogma raki group, walnut group and bogma raki + walnut group under electron microscopic examination. Comparing these three groups, there were no differences in the ultrastructural pathological changes. In the ultrastructural examination of the myelinated axons forming cochlear nerve, no ultrastructural pathology was detected in all the groups.

Imaging of the alpha-chain extensions of fibrinogen

1983 ◽  
Vol 41 ◽  
pp. 604-605
Author(s):  
Todd M. Price ◽  
M. L. Rudee
Keyword(s):  
Electron Microscopy ◽  
Amorphous Carbon ◽  
Microscopic Examination ◽  
Plasma Proteins ◽  
Polymeric Materials ◽  
Electron Microscopic Examination ◽  
Biological Materials ◽  
Mica Surface ◽  
Electron Microscopic ◽  
Alpha Chain

Amorphous carbon, as well as a few polymeric materials, are used routinely as substrates for the electron microscopic examination of macrorno1ecules. Replication of molecules from a cleaved mica surface is also used. The choice is ty pically made on the basis of convenience, and limited to commonly used materials.In the course of research on the interaction of plasma proteins with several non-biological materials we observed that the use of substrate materials that were not typical in electron microscopy produced images that revealed hitherto unobserved features of certain macromolecules. This paper will describe the techniques we have developed to image additional features of fibrinogen, give some additional results, and describe some experiments undertaken to elucidate the basis of the technique.

A Freeze-Fracture Technique for Examining Human Stratum Corneum

1972 ◽  
Vol 30 ◽  
pp. 298-299
Author(s):  
Daniel P. Hannon
Keyword(s):  
Electron Microscopy ◽  
Sample Preparation ◽  
Stratum Corneum ◽  
Microscopic Examination ◽  
Freeze Fracture ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Human Stratum Corneum ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron

Human stratum corneum is a difficult tissue to process for electron microscopic examination. Most of the difficulty is due to the inability of the chemical fixative to adequately preserve all of the constituents of this tissue. As a result, during sectioning, breaks occur between cells creating voids which preclude any studies of these areas. Also, because the fixative is usually in an aqueous medium, studies of hydrated or dehydrated states are impossible. However, these problems can be overcome by using an alternative method of sample preparation, freeze-fracture electron microscopy.Samples of human skin both untreated and soaked for 20 minutes in 20% glycerin were cut into strips 1 mm wide by 2 mm long and placed in specially made copper discs with a 1 mm deep central cup. Freezing was accomplished by immersion in liquid Freon 22.

A Comparative Study of Fractographic Replicas

1974 ◽  
Vol 32 ◽  
pp. 566-567
Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon
Keyword(s):  
Electron Microscopy ◽  
Electron Microscopic Examination ◽  
Direct Examination ◽  
Electron Microscopic ◽  
Reliable Technique ◽  
Service Failures ◽  
Transmission Electron ◽  
Mode Of Failure ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.

Properties of Isolated Mitochondria of Agaricus Bisporus: Their Relationship to Dormancy and the Germination of Spores

1973 ◽  
Vol 31 ◽  
pp. 458-459
Author(s):  
K. S. McCarty ◽  
R. F. Weave ◽  
L. Kemper ◽  
F. S. Vogel
Keyword(s):  
Mitochondrial Dna ◽  
Ethidium Bromide ◽  
Microscopic Examination ◽  
Agaricus Bisporus ◽  
Osmotic Shock ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Isolated Mitochondria ◽  
Dna Strands ◽  
Cytoplasmic Ribosomes

During the prodromal stages of sporulation in the Basidiomycete, Agaricus bisporus, mitochondria accumulate in the basidial cells, zygotes, in the gill tissues prior to entry of these mitochondria, together with two haploid nuclei and cytoplasmic ribosomes, into the exospores. The mitochondria contain prominent loci of DNA [Fig. 1]. A modified Kleinschmidt spread technique1 has been used to evaluate the DNA strands from purified whole mitochondria released by osmotic shock, mitochondrial DNA purified on CsCl gradients [density = 1.698 gms/cc], and DNA purified on ethidium bromide CsCl gradients. The DNA appeared as linear strands up to 25 u in length and circular forms 2.2-5.2 u in circumference. In specimens prepared by osmotic shock, many strands of DNA are apparently attached to membrane fragments [Fig. 2]. When mitochondria were ruptured in hypotonic sucrose and then fixed in glutaraldehyde, the ribosomes were released for electron microscopic examination.

Artifact-free electron microscopic immunocytochemistry on rat brain tissue

1991 ◽  
Vol 49 ◽  
pp. 272-273
Author(s):  
Veronika Burmeister ◽  
N. Ludvig ◽  
P.C. Jobe
Keyword(s):  
Microscopic Examination ◽  
Free Electron ◽  
Electron Microscopic Examination ◽  
Ultrastructural Localization ◽  
Rabbit Serum ◽  
Electron Microscopic ◽  
Electron Microscopic Immunocytochemistry ◽  
Phosphate Buffered Saline ◽  
Rat Brain Tissue ◽  
Immune Rabbit

Electron microscopic immunocytochemistry provides an important tool to determine the ultrastructural distribution of various molecules in both normal and pathologic tissues. However, the specific immunostaining may be obscured by artifactual immunoreaction product, misleading the investigator. Previous observations show that shortening the incubation period with the primary antibody from the generally used 12-24 hours to 1 hour substantially reduces the artifactual immunostaining. We now extend this finding by the demonstration of artifact-free ultrastructural localization of the Ca2/calmodulindependent cyclic nucleotide phosphodiesterase (CaM-dependent PDE) immunoreactivity in brain.Anesthetized rats were perfused transcardially with phosphate-buffered saline followed by a fixative containing paraformaldehyde (4%) and glutaraldehyde (0.25%) in PBS. The brains were removed, and 40μm sections were cut with a vibratome. The sections were processed for immunocytochemistry as described by Ludvig et al. Both non-immune rabbit serum and specific CaM-dependent PDE antibodies were used. In both experiments incubations were at one hour and overnight. The immunostained sections were processed for electron microscopic examination.

A New Human Breast Tumor Cell Line

1975 ◽  
Vol 33 ◽  
pp. 388-389
Author(s):  
R.E. Nordquist ◽  
R.M. Wasik ◽  
P.J. Riggs ◽  
P.L. Munson ◽  
F.B. Schafer
Keyword(s):  
Electron Microscopy ◽  
Cell Line ◽  
Calf Serum ◽  
Tumor Cell Line ◽  
Electron Microscopic Examination ◽  
Epithelial Cell Line ◽  
Electron Microscopic ◽  
Fixed Tissue ◽  
Excised Tissue ◽  
Caucasian Female

An infiltrating ductal cell carcinoma was removed from the breast of a postmenopausal Caucasian female. The excised tissue was divided into three parts; one part for electron microscopy, one part for tissue culture and the remainder frozen for immunological studies.The tissue for culture was minced finely with sterile razor blades and cultured in Falcon flasks containing Eagel's MEM supplemented with 10% heat denatured fetal calf serum. The tissue for electron microscopy was fixed in 6.25% glutaraldehyde in 0.1 M PO4 buffer plus 5% sucrose and postfixed in 1% OsO4 in the same buffer. The fixed tissue was dehydrated in graded ethanol and embedded in Spurr.The tissue which was cultured began to grow out after approximately six weeks and became a continuous epithelial cell line which was designated BOT-2 (Breast Original Tumor). Electron microscopic examination revealed that these cells had epithelial characteristics, i.e. the presence of tonofilaments and well formed desmosomes.

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