Short Separation Time Research Articles

Concentration and purification of plant pathogenic viruses by field step electrophoresis

Concentration and purification of plant pathogenic viruses by field step electrophoresis comprises a new and rapid preparative method with high throughput and short separation time. With this technique and combinations of field step and zone electrophoresis it is possible to purify plant pathogenic viruses from several contaminants in one separation step. Another application of field step electrophoresis allows the separation of viruses from each other.

Small-column chromatofocusing of cerebrospinal fluid and serum immunoglobulin G

Chromatofocusing performed by the Pharmacia fast protein liquid chromatographic system equipped with a specially designed small column was applied for examinations of submilligram quantities of cerebrospinal fluid and serum immunoglobulin G. The separations were based on a pH gradient between 9.5 and 6.0. Mono- or oligoclonal immunoglobulin G components having p I values within the optimal working range of the gradient were easily identified and the findings differed clearly from those of normal immunoglobulin G. The capacity to detect abnormal immunoglobulin G components compared well with previous experiences from the commercially available Mono P column. The small column offers advantages by having a shorter separation time, a decreased dilution of sample in the eluate and a lower consumption of start and eluent buffers.

An Agarose Gel Electrophoretic Method for Typing Phosphoglucomutase-1, Esterase D, or Glyoxalase I

A conventional agarose gel electrophoretic method was described for typing phosphoglucomutase-1, esterase D, or glyoxalase I as single systems. Bloodstain extracts were absorbed into 1-mm-thick agarose gels via an application mask. The electrode wick distance was 12 cm and electrophoresis was carried out at 400 V at 6 degrees C. The electrophoretic run times were 30 min for glyoxalase and 1 h for esterase D or phosphoglucomutase. This method is reliable and produces highly resolved band patterns. Additionally, the shorter separation times as a result of the increased voltage gradient permitted typing of more samples in a given time period compared with presently used methods. This technique requires little technical expertise and can be incorporated into the laboratory at a minimal cost.

Procedure for simultaneous phenotyping of genetic variants in cow's milk by isoelectric focusing.

A method is described which allows the simultaneous separation of all polymorphic protein fractions in cow's milk in one single run. The separation could be achieved by isoelectric focusing in ultrathin-layer polyacrylamide gels. The method is especially suitable for screening purposes because it combines low costs, high resolution and short separation time.

Separation of gangliosides by anion-exchange chromatography on mono Q™

A new type of strong anion-exchange resin, Mono Q™, has been used in the seapraton of brain gangliosides. The resin consists of monodisperse particles (9.8 μm) adn was used in prepacekd columns with a bed volume of 1 ml. The gangliosides were separated into mono-, di-, tri- and tetrasialoganglioside fractions by a discontinuous gradient of potassium acetate in methanol. The separation was complete in a volume of 50 ml. The major advantages of the new procedure compared to conventional methods are the shorter separation time, higher loading capacity and recovery of separated ganglioside fractions in small solvent volumes. The procedure was applied to the separation of gangliosides from normal human and GM2-gangliosidosis brain.

Schlieren photography of second-sound shock waves in superfluid helium

A conventional schlieren system has been used to study second-sound shock waves produced in a shock tube with optical windows. Initially planar shocks are observed to remain so, even after several reflections from the end walls. No interaction of the shocks with the side wall boundary layers is seen, attesting to the thinness of these layers. Second-sound shocks are reflected from the liquid–vapor interface, producing transmitted gasdynamic shocks and reflected second-sound shocks. Several strong shocks are fired with short separation times, generating observable fluctuations in the fluid.

Isotachophoretic analyses of metabolites of cardiac and skeletal muscles in four species.

We studied ATP and concentrations of other metabolites in cardiac and skeletal muscles from different species (frog, hamster, guinea-pig, and dog), using analytical capillary isotachophoresis. The method had several advantages for quantitative analysis of tissue metabolites: short separation time, high sensitivity, high resolution, and good reproducibility. It was also possible to detect a number of compounds simultaneously, including ATP, ADP, AMP, cyclic AMP, creatine phosphate (CP), inosine monophosphate, NAD, NADH, glucose-6-phosphate, pyruvate, and inorganic phosphate. Generally, the concentrations of high-energy phosphates (ATP and CP) in the cardiac muscle were significantly lower than those in the skeletal muscle, in all species tested, except for hamster where the concentration of CP in the skeletal muscle was comparable to that in the cardiac muscle. In mammals, ATP and CP concentrations were comparable in the atrium and ventricle while the concentration in the frog ventricle was significantly higher than that in the atrium. The data obtained by this isotachophoretic analysis were comparable to the data reported by the use of other conventional analytical methods. The significance and reliability of isotachophoresis in the determination of the various metabolites in the cardiac muscle were discussed.

Determination of tritiated digoxin and metabolites in urine by liquid chromatography

A liquid chromatographic method for the determination of digoxin, digoxigenin, its mono- and bisdigitoxoside and dihydrodigoxin in urine is described. Doses of 100 μCi of [12α- 3H] digoxin and 0.5 mg (640 nmol) of digoxin were administered orally to eight healthy volunteers. The compounds were extracted from urine with methylene chloride containing 3% of heptafluorobutanol. After separation, fractions corresponding to digoxin and the metabolites were measured by liquid scintillation counting. Conjugates of the glycoside metabolites were determined indirectly after pre-treatment of the samples with β-glucuronidase—arylsulphatase. The detection limit was 0.1 nmol/l. Metabolites amounting to 0.5% of digoxin were assayed with a relative standard deviation of 5%. The advantages of the method are a high recovery in the extraction step, short separation times and the possibility of separate assay of dihydrodigoxin.

A low-cost medium-pressure liquid chromatography system for preparative separations

On the basis of theoretical and economic considerations a medium-pressure liquid chromatography system for preparative separations was developed. The choice of stationary phases with an average particle size of about 50 μm allows a dry column packing technique and makes possible short separation times with low pressure drop. The columns can therefore be constructed of glass. Their design is very simple, the end fitting is uniform for all column sizes. A special column head ensures optimum solvent distribution which enables the use of large diameter columns without loss in performance. Measurements under analytical conditions confirmed HETP's less than 300 μm for all column sizes.

Gas‐liquid chromatography of serum bile acids using glass capillary columns

AbstractThe proposed combination of a rather simple procedure for sample preparation with capillary gas‐liquid chromatography using a barium carbonate/polyethyleneglycol 20,000 column and a Grob‐type on‐column injector permits measurement of bile acids in serum with high separation efficiency, short analysis time and complete separation of bile acids from cholesterol. The method can be adapted to combined capillary gas‐liquid chromatography ‐ mass spectrometry.

A new concept for rapid non-equilibrium T 3 uptake measurements

The copper form of the Chelex TM resin can be used in conjunction with centrifugation to separate free T 3 from T 3 that binds to the thyroxin binding globulin (TBG). This use of ligand exchange chromatography was tested using test sera that cover the range typically found in T 3 assays. Results show a coefficient of variation for the test sera of ±5%. The major advantages of this procedure are short incubation and separation times (less than 5 min).

Continuous Flow Electrophoretic Separator for Biologicals

In the near absence of gravity, a continuous-flow type of electrophoretic separator can be operated with a much thicker separation chamber than is possible under 1 g conditions. This should permit either better resolution or shorter separation time per unit of sample. An apparatus to perform experiments on sounding rockets is under development and will be described. The electrophoresis cell is 5 mm thick by 5 cm wide with 10 cm long electrodes. It is supplied with buffer, sample, and coolant at about 4 C through the use of a passive refrigerant system. UV sample detection and provision for recovery and cold storage of up to 50 sample fractions are now being added to the basic unit. A wide range of operating conditions are electronically programmable into the unit, even up to a short time before flight, and a further range of some parameters can be achieved by exchanging power supplies and by changing gears in the motor drive units of the pump. The preliminary results of some separation studies on various biological products using a commercially available electrophoretic separator are also presented.

Silver Loaded Aluminosilicate as a Stationary Phase for the Liquid Chromatographic Separation of Unsaturated Compounds

Microparticulate silica gel was treated with sodium aluminate to give a polyanionic surface which could readily exchange its counter ions for silver ions. The Ag-support is highly selective for unsaturated geometric isomers. The system was successfully applied to separate isomers of permethrin—a new synthetic pyrethroid pesticide, and series of isomers of C18 and C16 fatty acids. It gave short analysis time and good separations. Silver complexation was evident in the Ag-support in comparison with plain silica gel and sodium aluminosilicate. The new column did not suffer from Ag bleeding problems associated with some earlier works.

Detection of biochemical mutants in mice

Several bioanalytical techniques including electrofocusing, two-dimensional technique comprising electrofocusing and electrophoresis, and chromatography have been evaluated and improved to provide a method for detecting gene mutations in mice. The use of 1 mm gels for both electrofocusing and electrophoresis in the two-dimensional technique resulted in better resolution, shorter separation time, and reduced costs. An electrophoretic apparatus for the second direction electrophoresis has been designed which eliminated cutting of a flat gel into strips prior to electrophoresis. These changes reduced the total time for a two-dimensional separation to 4 h. The scope and application of isoelectric focusing in detecting gene mutations in mice have been improved by the agar contact replica method. This method allows the simultaneous analysis of several genetic loci besides facilitating automation of evaluation, documentation, and storage of zymograms. Preliminary studies on the detection of heritable metabolic disorders of amino acid metabolism in mice show a potential for such studies in estimating mutation rates in mice. Some possible techniques for such studies and their implications are discussed.

Rayleigh waves from high-gain long-period stations: Signal extraction, amplitude determination, and separation of overlapping wave trains

abstract For a signal-to-noise ratio between 0.2 and 0.1 on the original single-component records, amplitudes for Rayleigh waves over oceanic paths of 155° at station MAT and 98° at station KIP have been determined as 12 mμ and 24 mμ peak-to-peak, respectively, with a standard error of less than 11 per cent. In each case the processed correlation signal is the highest in a half-hour record. The method makes use of preliminary high-pass filtering and normalized reference earthquake-matched filtering, and takes full advantage of the well-dispersed oceanic surface wave. The method also provides high resolution of co-located events with short time separation, or of widely spaced events with Rayleigh waves arriving nearly simultaneously at a single station, when the summed vertical and radial matched filtered components are used. Examples include: (1) clear separation and amplitude determination at stations KIP and MAT of two MS = 6.5 earthquakes located 0.7° and 145 sec apart off the coast of central Chile; (2) clear separation at station KIP of a Novaya Zemlya mb = 4.8 event from interfering Rayleigh waves of an mb = 5.0 Kermadec Island earthquake arriving 120 to 140 sec prior to the searched event, with almost complete elimination of interference on the summed vertical and radial processed components; and (3) clear separation at station KIP of two co-located mb = 4.4 and 4.5 earthquakes 6 min apart off the coast of Chile, with determination of their amplitudes in the presence of interfering Rayleigh waves from two central Alaska earthquakes, the first (mb = 4.1) arriving 15 min prior to the first Chile Rayleigh wave and the second between the two Chile arrivals. The single-station threshold reached (10 and 25 digital units, p-p) for stations MAT and KIP at 155° and 98°, respectively, corresponds to an MS = 3.3 and probably can be improved further.

The application of the equivalent annulus width concept in thermal diffusion separations

The equivalent annulus width concept is used to characterize a small commercial thermogravitational thermal diffusion column and its validity checked experimentally by separating batchwise in the column mixtures of n-heptane—benzene with different initial concentrations. The equation of Ruppell and Coull was used to analyse the data in the short separation times range and determine the equivalent annulus width. Good agreement was obtained between the experimental and predicted time-separation curves when using the equivalent annulus width value and on averaged value of the thermal diffusion constant. A new method is presented for the simultaneous determination of the equivalent annulus width and the thermal diffusion constant of a binary mixture from a single set of experimental data.

A New Time-Sort Pitfall Trap

The trap described in this paper was designed for shorttime separation of faunal collections. Scientists investigating the ambulatory invertebrate fauna have used pitfall traps whenever separation of the catch into definite time periods was desired (Williams 1958; Greenslade 1964; Merrett 1967; Duffey 1972). Pitfall traps were thought to be applicable in a study of the activity periods of surface prey species to a desert grassland spider, Agelenopsis aperta (Gertsch). Since we found it inconvenient to service a large number of traps at required 4-h intervals, we needed a trap which would provide continuous sampling with short-time intervals.

Short-Time-Interval Behavior of Photon Echoes in Ruby near Level Crossings

The behavior of photon echoes near level anticrossings is described in terms of the magnetic-field-dependent mixing parameters. The general features of level-crossing behavior are obscured for most cases in dilute ruby and are dominated instead by strong spin-dependent decay resulting from Cr-Al interactions. However, new experiments at short time separation ($\ensuremath{\tau}=32$ nsec) between pulses have permitted observation of the predicted photon-echo anticrossing signals in ruby, and may be applied to other atomic systems.

Fully automated high-speed ion-exchange chromatography of amino acids

A procedure based on ion-exchange chromatography was deveoped which separates the amino acids present in protein hydrolysates with an automatic elution cycle which is repeated every 63 min. Forty samples in a row can be run completely unattended. Short separation times were achieved by optimizing chromatographic parameters and by reducing extra column band widening caused by sample loading and the delay time in the analytical system. A linear relationship exists between plate height and carrier velocity in the flow rate range investigated. Thus, diffusion coefficients in the stationary phase could be calculated for a number of amino acids.

長さの継時比較における時間誤差の因子分析 AL理論の観点より

There have been long controversies among the theories of “time-error”, for example, the theory of memory image (Fechner-Lehman), the trace theory (Köhler), the theory of assimilation (Lauenstein), the theory of Einstellung (Woodraw), and so on. However, a unitary conclusion will be given to the controversies in a near future. It seems that all these theories have already carried out their missions, and a new idea must be presented to give a definite unitary explanation to the “time-error”. Thus, Freeman and Sharp (1941) wrote that this new idea must be such one as to give a definite unitary explanation to the problems of “time-error” which will change according to the (1) magnitude of time-separation between two stimuli, (2) sort of the stimuli in its back-ground, (3) levels of intensity of the stimuli, (4) repetition of experiment.What will be the new idea which will be able to explain the “time-error” unitarily? However, the author believes that it is necessary to reexamine the results of researches concerning these problems by applying factor analysis, before constructing a new idea, because, so many data and theories have been accumulated that interpretation of foctors may be easy with the help of these informations. The factor analysis may be one of the best ways of giving a definite unitary explanation to the problems of “time-error”. The present experiment is designed from this viewpoint.A straight line which was illuminated by weak light was presented to a subject in a dark room. The length of the standard stimulus was 150mm, and variable stimuli were 140, 142, 144……158, 160mm. Ss was always presented prior to Sv. The time-separation (P) was as follows: P…0.5, 1, 3, 5, 8, 12sec.The subjects were fifteen students who were requested to make nine category judgments for six times in each time-separation. The adaptation level (A) of each subject was computed by Helson's short-cut method. The “time-error” (TE) of each subject was computed by the formula TE=A-Ss. The centroid method was applied to analyse the inter-correlation coefficient matrix.Tentative conclusions are as follows:(1) when the time-separation is 12sec., all the factor loadings are not high and fall within ±. 40.(2) The first factor has high positive loadings on P=0.5 and 3sec.(3) The second factor has high positive loadings on P=5 and 8sec.(4) The third factor has high negative loadings on P=1 and 3sec.(5) The fourth factor has not any high loadings on P=1 and 3sec.(6) The effects of time-separation may be classified into two groups, 1) short time-separation which is equal to or less than 3sec., 2) long time-separation which is equal to or longer than 5sec. The first and third factors may be called “the short time-separation factors” which have high (positive and negative) loadings on the short time-separation and low loadings on the long time-separation. The second factor may be called “the long time-separation. factor” which has high loadings on the long time-separation and has low loadings on the short time-separation.