Liquid purification or separation – Processes – Liquid/liquid solvent or colloidal extraction or diffusing...
Reexamination Certificate
2001-12-20
2004-10-26
Drodge, Joseph (Department: 1723)
Liquid purification or separation
Processes
Liquid/liquid solvent or colloidal extraction or diffusing...
C210S512100, C210S702000, C210S787000, C494S017000, C494S019000, C494S037000, C422S063000, C422S072000, C436S045000, C436S177000, C436S178000
Reexamination Certificate
active
06808633
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to a centrifugal separator and a centrifugal rotor and also is related to a centrifuge separation method suitable for separating a sample solute from a solvent and recovering them individually using the centrifugal separator.
2. Description of the Related Prior Arts
Various efforts are being made to elucidate the mechanism of life by measuring polynucleotides such as DNAs and mRNAs in living organisms. Main practical approaches supporting these efforts include; (1) prove testing, which involves preparing a DNA prove with its sequence complementary with a target DNA one another, for determining whether the DNA prove can be hybridized with the target DNA and (2) PCR testing, which requires selection of a region where the target DNA sequence runs, for determining whether a fragment can be PCR-amplified using a pair of DNA primers or for measuring the length of the sequence of the amplified segment and examining the sequence itself.
Since the mechanism of living organs works by means of expression of a wide variety of genes while associating with each other, transcription of the genes contained in chromosomes must be comprehensively examined. In making an attempt to elucidate the mechanism of the development of cancer and hereditary diseases from an aspect of DNAs, it is required to compare mRNAs or identify extensively any difference(s) between normal and variant cells. To measure the mRNAs, first, the mRNAs are extracted from the cells, cDNAs are prepared using reverse transcriptase, and then the specific mRNAs are detected using prove testing or PCR. The methods getting a lot of attraction include Differential Display (Peng Liang and Arthur B. Pardee, Science 258, 967-972 (1992)), by which the mRNAs are compared between the cells or tissues, and Amplified Fragment Length Polymorphisms (WO093/06239). Based on PCR, the latter method amplifies the mRNAs using random primers or arbitrary sequence primers to get their patterns and compares the resulting patterns, allowing the transcription of the mRNAs between the cells or the tissues to be matched.
On the other hand, the Finger Printing method focusing on genome or a specific DNA region has been used on a pilot basis. The Restriction-Enzyme Landmark-Scanning method, first, uses NotI, a rare cutter, to cut the genome into cutting sites, in which labels are introduced. Second, the resulting cutting sites with labels are separated by agarose electrophoresis. The DNAs separated by agarose electrophoresis are further cut into smaller fragments in a gel using a 4-base restriction recognition enzyme and then an agarose gel is spread on a polyacrylamide slab gel. This means that this method is designed to detect a wide variety of genome-derived DNA fragments by 2-dimensional electrophoresis.
In the fields around genome analysis, a need has been increasingly boosted for a method of higher efficient determination of DNA sequences. In place of conventional, manual-based methods of determination of DNA sequences, by which the DNA fragments are labeled using a radioisotope and the lengths of the DNAs are measured by gel electrophoresis, a device (a DNA sequencer), which labels the DNAs with a fluorophore to optically auto-detect the DNA fragments by irradiating a light beam while gel electrophoresis is proceeding, and the determination method of DNA sequences with the DNA sequencer have being spread. The determination methods of DNA sequences, called the Sanger and Dideoxy Chain-Termination methods, are those by which a DNA oligomer, a primer, is hybridized with a target DNA, various lengths of DNA fragments are prepared to be used in determination of DNA sequences by complementary-strand synthesis using an enzyme, and the lengths of the DNA fragments are measured by gel electrophoresis to determine the DNA sequences. The total base length to be determined at the same time by the determination method of DNA sequences may span over from 400 to 700 bases depending on the ability of the gel to separate the fragments. Note that since the determination methods target largely at the genomes and mRNAs and in many cases, the base length to be determined is several kilobases for the mRNAs and is longer than several kilobases for the genomes, respectively, the sequencer cannot determine the entire DNA sequence at the same time.
Conventionally, the Shotgun method has been used for determination of long DNA sequences with several kilobases to several tens kilobases. In case of the Shotgun method, the DNAs are randomly cut into fragments using, for example, an ultrasonic wave, the DNA fragments are cloned and embedded into culture media such as
Escherichia coli
, and then after colonial cultivation,
Escherichia coli
is cultivated in each colony to increase the number of DNA fragment copies. Subsequently, sample DNAs are extracted and DNA analysis, for example, determination of DNA sequences, is carried out. In principle, the Shotgun method, which randomly controls the DNA fragments to remove any overlapping between the DNA fragments, leading to elucidation of a linkage between the DNS fragments, is suitable for the long DNA strands with their sequences unknown and used in the Genome Sequencing Project as a primary method.
The examinations using a DNA prove or PCR, Differential Display, analysis of amplified fragment length polymorphisms, Restriction-Enzyme Landmark-Scanning method, and the determination method of DNA sequences mentioned above are implemented be means of auto-measurement instrumentation with electrophoresis and fluorescent detection by laser irradiation combined therein or auto-hybridization detection instrumentation.
On the other hand, since sample preparation exploiting skills of molecular biology for gene analysis and gene diagnosis involves various processes such as purification of nucleic acid and hydrogen reaction, it is often required that liquid samples should be handled on a minute scale of micro litter. Liquid sample handling necessary for preparation of these samples comprises quantification, transport, retention, mixture, and storage, for each of which a suitable liquid-sample handling tool is commercially available.
As a handling tool for quantification and transport of the liquid samples, a micropipette with a plastic chip is widely used. The micropipette can be used to suck and discharge the liquid sample through an air cylinder using a disposal, plastic chip tube. Plastic sample tubes and multi-well plates are commonly used for retention, mixture, and storage of liquid. Intended to handle liquid samples during purification, in particular, column vessels with a filter are widely spread. Full-automatic equipment, which prepares the samples using these devices and jigs, has been introduced in the market.
Conventionally, the ethanol precipitation method has been usually used for manual preparation of the samples. In case of the ethanol preparation method, the DNAs or the RNAs are precipitated and separated by adding ethanol to prepare a 60-70% of DNA or RNA sample solution in a certain ion environment, followed by centrifugation. Alternately, to remove proteins and lipids from living samples for purification of DNAs or RNAs, the technique, by which phenol is added to a sample mixture to denature and precipitate proteins or by which the lipids are removed by the chloroform extraction method, has been usually used. These techniques requiring centrifugation are essential to molecular biology.
In relation to conventional centrifugation, first of all, centrifugal tubes having samples loaded are mounted on the centrifugal rotors of the centrifugal separator. A batch processing, in which multiple centrifugal tubes are processed at the same time, is essential to centrifugation. In many cases, the quantity of a sample liquid depends on the kind of the sample and when the multiple samples are centrifuged at the same time, the centrifugal tubes associated with the individual samples must have been balanced (the weights of two centrifugal tubes are man
Fukuzono Shinichi
Ikeda Yukiko
Murakawa Katsuji
Okano Kazunori
A. Marquez, Esq. Juan Carlos
Drodge Joseph
Fisher Esq. Stanley P.
Reed Smith LLP
LandOfFree
Centrifugal separator and sample preparation device using... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Centrifugal separator and sample preparation device using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Centrifugal separator and sample preparation device using... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3323734