Abstract: The filling of an internally coated capillary with a gel in its polymerized state without damaging the gel. The coating prevents bonding of the gel to the inside of the capillary. The gel comprises up to 6% acrylamide and 0-5% crosslinker. The gel can be advantageously and conveniently used in automated electrophoresis systems for automatic replacement of spent gel.

Abstract: Method for substituting a substitution compound for the hydrogen of a support bound primary hydroxyl group. The support bound primary hydroxyl group is treated in an organic, substantially anhydrous solvent in the presence of a tertiary amine base and the substitution compound.The substitution compound has a positive moiety and a negative moiety. The positive moiety is selected from the group consisting of trityl, pixyl, and derivatives thereof.The reagent is selected from the group consisting of tetraalkylammonium salts, inorganic salts, and mixtures thereof. Each reagent has a cation and an anion moiety.The cation moiety of the reagent is more electropositive than the positive moiety of the substitution compound. This relationship enables the reagent to attract the negative moiety of the substitution compound.

Abstract: Ionic species and method for the quantitation of sample constituents utilizing capillary zone electrophoresis analysis are disclosed. As disclosed, at least one ionic species having a charge density of betwen about 0.02 and about 0.001 is added to the sample. Benzoic acid is a preferred ionic species. Quantitation of a sample constituent can be derived by normalizing the constituent species with the ionic species.

Abstract: Disclosed herein is a liquid scintillation solution useful for alpha particle emission and beta particle emission discrimination. Most preferably, the liquid scintillation solution comprises at least one naphthalene derivative enhancing agent; at least one solvent; and at least one fluor. In a particularly preferred embodiment, the liquid scintillation solution comprises di-isopropyl naphthalene as the enhancing agent; phenylxylethane as the solvent; and 2-(4'-biphenyl)-6-phenylbenzoxazote as the fluor.

Abstract: A method is provided for determining the sequence of nucleotides on a single strand DNA molecule. The single strand DNA molecule is attached to a leader oligonucleotide and its complementary strand to a solid state support. Fluorescently-labeled 3'-blocked nucleotide triphosphates, with each of the bases A, G, C, T having a different fluorescent label, are mixed with the bound DNA molecule in the presence of DNA polymerase. The DNA polymerase causes selective addition of only the complementary labeled NTP, thus identifying the next unpaired base in the unknown DNA strand. The 3'-blocking group is then removed, setting the system up for the next NTP addition and so on. The sequence is repeated until no more fluorescently-labeled NTPs can be detected as being added by the polymerase.

Abstract: The present invention is directed to a technique that provides enhanced separation resolution in electrophoresis. This technique involves the use of a time-varying field strength, which may be progressively increasing or decreasing, constant or otherwise, as a function of time. The shape of the field strength with respect to time may be continuous or stepwise over time, monotonic or otherwise.Because the mobility of different size species is a function of the applied electric field, the use of a nonuniform (time varying) electric field increases the resolving power of electrophoresis. This technique has been found to provide enhanced resolution of double-stranded DNA molecules in capillary polyacrylamide gel electrophoresis. It has been found that enhanced separation of DNA restriction fragments of 1 to more than 1000 base pairs in size has been achieved employing the technique of the present invention.

Abstract: A method and apparatus for generating scintillation pulse height distribution spectrum with respect to a square root representation of pulse height. Pulse height data are pooled into variable size windows of which the average energy level is approximately proportional to the square of the corresponding window number. The square root representation is accomplished by choosing the size of each window according to an arithmetic series of a constant difference between windows.

Abstract: The present invention provides processes for isoelectric focusing ("IEF") and associated detection, which incorporates a dynamic means of electroosmotic flow ("EOF") control during IEF and/or after IEF to effect solute mobilization. In accordance with the present invention, the EOF control during IEF and/or solute mobilization after IEF are accomplished by applying an external electric field, relative to an internal electric field, to modify the electroosmotic flow in the capillary. This can be done by disposing a conductive member at one or more locations outside and along the buffer column in the capillary. The conductive member may be statically charged or caused to conduct a current to create the external required electric field. The applied external electric field may be adjusted, relative to the internal electric field, during IEF as necessary to reduce or completely suppress EOF to prevent flow of the buffer.

Abstract: A method of positively deciphering a DNA sequence of a sample by comparing data of two electropherograms obtained from separate electrophoresis of products from two complete sequence reactions of the same sample, whereby dideoxynucleotide terminators of different but matched concentration ratios are employed for the two reactions. The sequencing chemistry is chosen to result in terminator-concentration dependent in peak intensity in the electropherograms. By appropriately choosing the matched concentration ratios of the terminators used in the two sequence reactions, ambiguities in the discrimination of the peaks in the result of one sequence reaction can be resolved by comparing the result of the other sequence reaction. The sequence of the sample can therefore be deciphered to a high degree of accuracy. For fluorescence detection of electrophoresis of the sequence reactions, three ddNTP terminators and one fluor are included in the sequencing chemistry of each reaction.

Abstract: A method for the generation of phenylthiocarbamyl (PTC) amino acids from phenylthiohydantoin (PTH) or anilinothiozolinone (ATZ) amino acids. The method involves a base-catalyzed ring opening of the PTH or ATZ in the presence of a reducing agent. The method affords an alternative to the established aqueous acid conversion reaction of the Edman degradation in which ATZ and PTC amino acids are converted to the PTH amino acid. A further method is described for the generation of reactive ATZ amino acids from PTH amino acids. These methods facilitate the analysis of protein at low molar amounts by allowing the synthesis of amino acid derivatives which can be analyzed in quantities which are much lower than those required for conventional PTH amino acid analysis.

Abstract: Disclosed herein is a dynamic coating buffer useful in the analysis of samples by open-tube capillary electrtophoretic methods using untreated fused silica capillary columns. The dynamic coating buffer comprises at least one agent having at least two dissociation constants, and high ionic strength characteristics, said agent having a molarity range of from about 0.2M and about 1.0M and a pH range of from between about 3.0 and 11.0. A particularly preferred dynamic coating buffer comprises 0.5M sodium phosphate.

Abstract: A centrifuge rotor overspeed protection system which can operate with rotors of at least two speed ranges. A set of coding elements are provided on the rotors coded to represent the actual maximum safe speed rating of the rotor. An additional set of coding elements coded to correspond to the maximum speed in the lower speed range are also provided such that the rotor can be operated at the maximum speed possible in a prior art centrifuge designed for operation in the lower speed range. The detection circuit for the coding elements automatically adjusts the detection threshold depending on the average values of the sensor output peaks corresponding to the codes.

Abstract: Disclosed herein is a capillary column containing a dynamically cross-linked composition and method of use. In a particularly preferred embodiment, the dynamically cross-linked composition comprises: 1.0% polyethylene oxide; 1.0% polyethylene glycol; 1.0% ethylene glycol; 100 mM TRIS-CHES buffer; and 0.1% sodium dodecyl sulphate, where the pH of the composition is between about 8.0 and about 9.0 and the viscosity of the composition is less than about 500 centipoise. The disclosed compositions can be used for the analysis of surfactant:proteinaceous material complexes and the generation of calibration curves over an extensive range of molecular weights, using capillary electrophoretic techniques. The disclosed compositions are particularly suited for capillary electrophoretic systems having UV-based detection.

Abstract: A redundant safety lock for securing a centrifuge lid in its closed position. The lock includes a disc having an aperture through which a striker on the lid can be inserted in an unlocked position. The disc is rotated to a locked position such that the striker cannot be withdrawn through the aperture to open the lid. The weight distribution of the disc is substantially symmetrical about its center of rotation. The disc is therefore less susceptible to dislodging form its locked position upon perturbation from shock experienced.

Abstract: External markers and method for the identification of protein-and-peptide-containing samples utilizing capillary electrophoresis analysis. As disclosed, at least two external markers are added to the sample: one of the markers is a neutral charge species and one of the markers is an ionic species. Dimethylformamide is a preferred neutral charge species and benzoic acid is a preferred ionic species. Identification of constituent species is determined by comparing the migration ratios of the constituent species with migration ratios for each constituent species member.

Abstract: A direct current power supply which incorporates an alternating current circuit segment so as to enable the use of a reactive component as an impedance limiting circuit element. The alternating current is produced by pulse width modulation regulation of raw direct current and DC to AC inversion. A feedback circuit is provided to regulate the pulse width modulation in accordance with the direct current output by the power supply so as to obtain a desired output current.

Abstract: A method of measuring and compensating stray light in absorbance analysis that use a multiple element array detector wherein one or more of the elements of the diode array are utilized to detect stray radiation in the absence of primary radiation including higher order diffracted radiation. In one aspect, the atmosphere is used to filter all primary radiation below a particular wavelength so that one or more array elements corresponding to detection below such wavelength can be dedicated to the detection of only stray radiation. Detection of higher order diffractions can be prevented by dividing the total spectrum into intervals and detecting these intervals in sequence. In another aspect, a diode array is designed to include additional elements along one side of the array outside the exposure of the primary radiation for the sole purpose of detecting stray radiation.

Abstract: A means of sealing a centrifuge tube which makes use of the hydrostatic pressure of the sample solution contained in the tube to perfect a tight seal during centrifugation. The filler stem is plugged with a plug which is supported in the rotor cavity. The hydrostatic pressure forces the filler stem against the plug to effect a seal with a sealing force which is dependent on the hydrostatic pressure which is in turn dependent on the centrifugal force on the sample solution.

Abstract: A monochrometer having a stray light trap which substantially directs stray light away from light of wavelength of interest and/or absorb the stray light so as to substantially reduce the stray light component in the light of interest. The monochrometer has internal surfaces each having one of several optical characteristics.

Abstract: Method and electrolyte buffer useful in the analysis of samples comprising glycoproteins by capillary zone electrophoresis. The buffer comprises at least one agent capable of complexing with sugar moieties of glycoproteins. The buffer preferably further comprises at least one pH modifier. An embodiment of the buffer comprises boric acid as the complexing agent and sodium hydroxide as the pH modifier.