Chemistry: electrical and wave energy – Processes and products – Electrophoresis or electro-osmosis processes and electrolyte...
Reexamination Certificate
1999-12-14
2001-07-24
Jones, W. Gary (Department: 1655)
Chemistry: electrical and wave energy
Processes and products
Electrophoresis or electro-osmosis processes and electrolyte...
C204S456000, C435S006120, C435S007100, C436S094000
Reexamination Certificate
active
06264814
ABSTRACT:
The invention relates to apparatus for isolating and/or analyzing electrically charged biomolecules, illustratively to isolate and/or analyze nucleic acids, having a vessel made of a substantially rigid plastic and comprising a collection chamber to receive a reaction mixture of sample and reagents, the collection chamber being externally accessible through an intake aperture of the vessel, and furthermore two electrodes movable into the collection chamber to come into contact with the reaction mixture.
The invention moreover relates to a method for isolating and/or analyzing electrically charged biomolecules, preferably nucleic acids, by adsorbing charged biomolecules contained in a solution to an appropriate adsorbent, by separating the remnant solution and optionally washing the adsorbent, by detaching the biomolecules from the adsorbent and separating the biomolecules, and to using the apparatus of the invention in the method of the invention.
Apparatus of this species are used in biochemical analysis and in the peripheral field of modern pharmaceutical identification of active substances (HST=High Throughput Screening) in the most diverse domains, for instance in nucleic-acid analysis. Illustratively the patent document WO 97/34908, of earlier priority than the present application but published after the priority date of the present application, discloses apparatus of the species wherein the vessel besides a collection chamber also comprises a withdrawal chamber communicating through a transfer duct with the collection chamber. Nucleic acids to be isolated are electrophoretically moved from the collection chamber through the transfer duct into the removal chamber and there are enriched. Moreover the vessel is fitted at its base wall with a pipe stub allowing draining the collection chamber. On the whole the above described vessel is of complex design entailing substantial manufacturing cost. Especially as regards applications in which the apparatus cannot or is not allowed to be used again on given grounds, there is a need for a simpler and more economic problem resolution.
The discussion to follow of further documentation relates to further aspects of such apparatus calling for improvements and the methods of the state of the art used in their operation:
Illustratively further electrophoretic equipment is known using platinum electrodes. Platinum is highly resistant to redox processes and, being an inert electrode material, constitutes a durable solution. However the entailed high material costs, for instance of coated electrodes for single use, are a drawback. Moreover the coating of platinum surfaces is a complex engineering procedure. Plastic electrodes, for instance made of synthetic carbon (BIO Fonum Forschung und Entwicklung, GIT Verlag, 19
th
year, vol 12, 1996, p 584) also are state of the art. However such apparatus are unsuitable for single use because they cannot be made economically, for instance by injection molding. A survey of electrophoretic gel methods is described in “Electrophoresis Theory, Techniques; and Biochemical and Clinical Applications”, Ed. A. T. Andrews, ISBN 0-19-854633-5, Clarendon Press, Oxford 1986. Besides normal gel electrophoretic methods, also so-called plotting techniques are described in the above work as well as in a work by Southern (GB 88 10400, 1988), which require corresponding plate electrodes. On economic grounds, platinum electrodes are ruled out entirely. In general V2A steel may also be used.
The patent documents WO 95/12808 and U.S. Pat. No. 5,605,662 describe systems hybridizing nucleic acids and also employing a special electrode configuration. The heart of these documents is micro-apparatus wherein nucleic acids are hybridized. A special stringency check is carried out by electronic interactions with micro-electrodes. The surfaces of these micro-electrodes are made of a material allowing free transport of compensating ions. This apparatus is used to concentrate nucleic acids and to carry out corresponding hybridizations. By appropriately changing the electrode polarity, poorly hybridizing parts of nucleic acid can be removed.
The electrode is coated with an oligonucleotide and can be prepared by microlithography. The following materials are cited for the electrodes: aluminum, gold, silver, tin, copper, platinum, palladium, carbon, semiconductors and combinations thereof. The manufacture of these electrodes or the deposition of the electrodes on certain substances according to the patent documents WO 95/12807 or U.S. Pat. No. 5,605,662 as a rule is implemented by vacuum evaporation or evaporation coating techniques. If appropriately finished, the electrode surface may be coated with biologically active components such as nucleic acids.
The patent document WO 96/15440 describes another procedure requiring electrodes. This so-called electrochemiluminescent method generates a luminescence signal by exciting molecules at the surface of an electrode. Using magnetic fields, illustratively magnetic particles bearing appropriate luminescence labels are transported to the electrode surface. The special embodiment in this document is a reusable in-line cell. This cell comprises a preferably gold electrode. The matching electrode is a corresponding reference electrode. As a rule the matching electrode is a silver/silver-chloride system. All these procedures incur the drawback of using expensive noble metals for the electrode material and consequently are unsuitable for instance for a single-use apparatus.
The patent document WO 97/02487 describes a planar device in the form of a test strip to measure electroluminescence.
A procedure of electro-elution is described in “Methods in Enzymology 65” [pp 371-380, 1980]. Platinum electrodes are used.
A method for coating non-conducting plastic surfaces using avidin or streptavidin is described in the patent documents U.S. Pat. No. 4,656,252 and U.S. Pat. No. 4,478,914 Re. 31,712.
The German patent document A1 195 20 398 describes magnetic particles having a glass surface and which are suitable for isolating nucleic acids and which may be used in apparatus of the present application. A comparable procedure employing porous glass surfaces and covalent bonds is described in U.S. Pat. No. 5,601,979 for nucleic-acid hybridization.
The patent document WO 97/01646 discloses a procedure to electrochemically detect nucleic-acid hybridizations using electrodes consisting of substrates on a surface. According to the patent documents WO 92/20702; WO 92/20703; EP A1 0,618,923 and WO 96/27679, furthermore so-called peptide nucleic acids (PNA) can be advantageously used, besides nucleic acids, in hybridization.
On the other hand it is the objective of the present invention to create apparatus of the initially cited kind which is of simple design and can be manufactured economically.
The invention solves this problem by apparatus of the initially cited kind which furthermore comprises a tube unit made of an electrically non-conducting plastic and dimensioned and/or configured and/or mounted in such manner that at least part of its inside surface may be brought into contact with the reaction mixture contained in the collection chamber whereas the tube unit and one of the electrodes are designed in such manner that this electrode can be brought into contact, inside the tube unit, with the reaction mixture. Because the invention provides the tube unit, the design comprising a vessel with a separately formed removal chamber can be dropped and as a result the vessel is constructed in commensurately simple manner and manufactured correspondingly more economically. In the invention, the removal chamber is present inside the tube unit and as a result this tube unit, being a simple component, contributes only insignificantly to the manufacturing costs of the apparatus as a whole.
The tube unit may be configured inside the vessel in widely different ways:
Illustratively this tube unit may be affixed to one of the electrodes, preferably being attached to it, and it may be inserted into the vessel
Arent Fox Kintner & Plotkin & Kahn, PLLC
Bilatec Gesellschaft zur Entwicklung
Jones W. Gary
Lu Frank
LandOfFree
Apparatus and method for isolating and/or analyzing charged... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for isolating and/or analyzing charged..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for isolating and/or analyzing charged... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2495878