Glass Bead Method Research Articles

A glass bead method for picking bacterial colonies

A glass bead method for picking bacterial colonies

Optimization of extraction and PCR amplification of RNA extracts from paraffin-embedded tissue in different fixatives

A method was developed for fast and efficient isolation of RNA from paraffin-embedded tissue sections for subsequent PCR analysis. This method is based on the binding of RNA to acid-treated glass beads in the presence of a high molarity of guanidinium salt. It can be completed within an hour, and obviates the need for dewaxing and phenol/chloroform extractions. The effect of various fixatives and fixation times was tested and the amplification of actin mRNA fragments ranging in length from 82 to 507 bp was used to demonstrate the presence of RNA in the extracts. The method was compared to existing extraction techniques by studying the quality of the templates for reverse-transcriptase polymerase chain reaction amplification (RT-PCR), using virus-infected and mock-infected paraffin-embedded cell pellets as a model. PCR amplification of cellular and viral RNA was successful for RNA isolated by use of all extraction techniques, although the glass bead method was preferred for its simplicity and rapidity. Specimens fixed with formalin were found to be suitable for PCR, but the best results were obtained with acetone-fixed paraffin-embedded material. Dewaxing of tissue sections had no effect on the yield and quality of RNA extractions, and further purification of the extracts using gel filtration did not improve the results. After the protocols were optimized, rotavirus-infected cell pellets were used to demonstrate that extraction and amplification of dsRNA was possible. The information obtained from the studies with the model system was used for extraction of toroviral and rotaviral RNA from archival intestinal material. These data indicate that paraffin-embedded archival tissue can be used for RT-PCR analysis, adding an important technique to diagnostic pathology and retrospective studies.

Application of the freeze-blast method to disruption of cultured plant cells

The freeze-blast method with a ‘Cryo-Clean Blaster (CCB)′ was applied to disrupt liquid-cultured plant cells of Lavandula vera L 10 4-2154. Recovery of peroxidase and chlorophylls a and b by this method was relatively higher than that obtained by the glass beads method. Under hypertonic conditions, chloroplasts were also isolated without lysis of the cells.

Evaluation of the procedures for the measurement of water solubility and n-octanol/water partition coefficient of chemicals results of a ring test in Japan

A ring test by 19 labolatories in Japan was carried out in 1984 for the evaluation of the experimental manuals for the measurements of water solubility and partition coefficient (n-octanol/water). The experimental data obtained by the procedures in the manuals were collected by Environmental Agency, Japan. In the measurement of water solubility, this manual applies a modified batch method (the glass beads technique), whereas the OECD Test Guidelines suggests the use of the column elution method for chemicals having water solubility lower than 10 mg/L. Anthracene and flouranthene were used as test chemicals for the measurement of water solubility, and γ -hexachlorocyclohexane (γ -HCH) and 1,2,3-trichlorobenzene were used for partition coefficient. Good agreements were observed at a practical basis between the OECD methods and our methods for the results of mesurements of water solubility and partition coefficient. We concluded that the present ring test showed an advantage of the use of the glass beads method which requires only simple apparatus in water solubility measurement, and the HPLC method is very useful to measure partition coefficient because of the simplicity of procedure and the wide range of measurement, especially at higher values of partition coefficient.

Paucity of subtle myocardial injury after angioplasty delineated with MB CK

To determine the extent to which PTCA elicits subtle myocardial ischemic injury, 28 patients were studied prospectively. The presence of myocardial injury was assessed by analysis of frequent (q4 hours) serial samples of MB CK, a sensitive and specific marker of myocardial injury. Immediately prior to angioplasty, baseline 12-lead ECGs and blood samples for evaluation of total CK and MB CK were obtained. Additional ECGs were obtained immediately after the procedure and on the following morning, and serial samples for total and MB CK were obtained at 4-hour intervals for 24 hours. Patients requiring cardiac surgery within 24 hours after PTCA were excluded. Samples (n = 203) were assayed by the glass bead method. Total CK rose by more than 20 IU/L in only five patients, four of whom had received intramuscular premedication. Mean MB CK was 3.4 +/- 6.1 IU/L at 12 hours and 4.1 +/- 4.7 IU/L at 24 hours compared to 3.1 +/- 1.7 IU/L prior to angioplasty. Only one patient with obvious infarction had a value for MB CK above the normal range. Thus, uncomplicated PTCA is not accompanied by objectively detectable subtle myocardial injury.

低レイノルズ数領域における二円柱まわりの流れ

Two circular cylinders were towed at a uniform. speed in a tank filled with glycerin. Flow patterns around the models were visualized by means of aluminium dust or glass beads method when the plane containing the central axes of two cylinders were inclined to the forward direction at arbitrary angles.Separation of the flow from the cylinder surfaces occurs when gap between two cylinders is small.

Uterine estrogen receptor assayed by the controlled pore glass (CPG) method in adult rat after steroid administration.

The interaction of estrogen and androgen was studied at the estrogen receptor level of adult rat uterus by the in vivo experiment. Both the free and total estrogen receptor in the cytosol and nucleus were assayed by the controlled pore glass beads method [2]. Testosterone was given by daily injection for 5 days to the rats treated with estradiol dipropionate (long-acting estradiol) 3 or 5 days before. In the estradiol dipropionate-treated rats the plasma estradiol concentration remained at an extremely high level for 7 days and then decreased to 5-fold of that of proestrus control by the 14th day. There was no significant change in the uterine estrogen receptor of the adult rat with a high estradiol concentration induced by testosterone.

Visualization of Separating Stokes Flows

This paper provides photographs of separating Stokes flows. Silicone oil and glycerine were used as the working fluid. The aluminum powder method and the glass beads method were used for flow visualization. The flows studied are flows around bodies placed in a uniform flow, flows past bodies placed near a plane wall, flows past a fence, flows past a step, flows past a wall cavity, and flows near a sharp corner. It is found that there is a remarkable agreement between the experimental results and the theoretical ones.

Glass bead method for releasing contact inhibition

Glass bead method for releasing contact inhibition

けい光X線分析法による炭素鋼, 低合金鋼中の希土類元素の定量

In a recent study to improve the properties of steel by the addition of rare earth elements, a need arose for an accurate analytical method of these elements. An investigation was undertaken to determine 4 rare earth elements (La, Ce, Nd, and Pr) in the range of 0.005 to 0.15% by the X-ray fluorescent technique.In the absence of reliable standards, the glass-bead technique for odd samples such as drillings was developed. Rare earth elements were precipitated as the fluorides after dissolving 5g of the sample in sulfuric acid, and the filtered fluorides followed by ignition to oxides were mixed with sodium tetra borate and melted to prepare glass-bead.The glass-bead method provided for precision less than 2% of the amount present. A good agreement was obtained between the chemical and X-ray results.The advantages of the method are the facility of the construction of a calibration curve by using chemical reagents, the absence of interelemental effects because of the separation of rare earth elements, and the versatility to be applicable to other materials with minor modifications.The standard samples of low-alloy steel were furthermore prepared for the direct metal disk technique and a conventional procedure was taken with satisfactory results.

Early macromolecular changes after release of contact inhibition by the glass bead method.

EARLY MACROMOLECULAR CHANGES AFTER RELEASE OF CONTACT INHIBITION BY THE GLASS BEAD METHODGERALD M. KOLODNY, M.D.Audio Available | Share

Phytohemagglutinin-induced transformation and aggregation of guinea pig lymphocytes.

Mitogenic agents which cause a high percentage of blast transformation when added to short-term lymphocyte cultures also cause marked cell aggregation. Conditions which promote cell-to-cell contact may increase the blastogenic reaction as evidenced in antigen-stimulated lymphocyte cultures (1, 2). Removal of those cells capable of adhering to glass eliminates the transformation seen in antigen-stimulated cultures (1–3). Despite the evidence that cell contact is an important aspect of response to specific antigens, the relationship of marked aggregation seen with phytohemagglutinin (PHA) and other nonspecific mitogens to blastogenesis is less clear. Lymphocytes purified by the glass bead method still transform when treated with PHA (1, 2). Coulson (4) has observed PHA-induced transformation even when cells are embedded in agar prior to treatment so that cell contact is eliminated. In the agar system it would seem difficult to measure the magnitude of this response. In the present work, the response of guinea pig lymph node lymphocytes to PHA is related to the aggregation characteristics of the treated cells. Materials and Methods. Hartley strain inbred guinea pigs (Camm Research Institute, Inc., Wayne, N.J.) 300–350 g males were used in all experiments. These animals were immunized by subcutaneous injection into each hind footpad, 0.2 ml of alumprecipitated DPT antigen (Tri-Solgen, Eli Lily & Co.) at 10-day intervals. Ten to 20 days after the second immunization, the animals were sacrificed. Under aseptic conditions, popliteal lymph nodes were collected in TC 199 (Difco) with 20% fetal calf serum, gently minced, and expressed through a 100-gauge stainless steel wire mesh. This yielded a 98% single cell suspension which was washed twice and adjusted to a concentration of 4 × 106 cells/ml. A 0.5-ml portion of this suspension was then added to 1.5 ml of TC 199, with or without PHA (control), and cultured in vertical, tightly stoppered 15-ml round bottom Kimax tubes at 37° in 5% CO2-air. Cells were routinely harvested at 1, 48, and 96 hr. The PHA used in all experiments was from a lot prepared in this laboratory by the method of Börjeson et al. (5), contained 2.8 mg of protein/ml, and was stored frozen at —20°. A new vial was opened for each experiment. The optimum dose of PHA for a culture containing 1 × 106 cells/ml was 0.001 ml (2.8 μg of protein) /ml of culture.

Serum‐Protein Determination by the Glass‐Bead Method

Serum‐Protein Determination by the Glass‐Bead Method