Method of separating serum from whole blood

Details Method of separating serum from whole blood Method of separating serum from whole blood

1999-02-18

2001-05-01

Wallenhorst, Maureen M. (Department: 1743)

Chemistry: analytical and immunological testing

Including sample preparation

Liberation or purification of sample or separation of...

C436S016000, C436S054000, C436S069000, C436S174000, C422S073000, C422S105000, C210S645000, C210S767000, C210S808000

Reexamination Certificate

active

06225130

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to a method of preparing a serum sample from whole blood.
The type or concentration of blood components, such as metabolites, proteins, lipids, electrolytes, enzymes, antigens, and antibodies, is measured, in general, using a plasma or serum sample obtained by centrifuging whole blood. However, centrifuging takes labor and time. Particularly, centrifuging is unsuitable for an urgent case of measuring a small number of samples promptly and in site inspection, because of requiring a centrifuge and electricity. Thereupon, it has been investigated to separate serum from whole blood by filtration.
Several filtration methods using glass fiber filter have been developed wherein whole blood is charged into the glass fiber put in a column from one side of the column, and pressurized or evacuated to obtain plasma or serum from the other side (Japanese Patent KOKOKU Nos. 44-14673, 5-52463, Japanese Patent KOKAI Nos. 2-208565, 4-208856).
However, practical filtration methods capable of obtaining an amount of plasma or serum from whole blood necessary for measuring by an automatic analyzer have not been developed except a part of items, such as blood sugar.
On the other hand, the inventors developed a blood filter unit composed of a filter holder and a syringe. The filter holder is composed of a holder body which contains filter material and a cap which is screwed on the holder body. The filter material consists of, e.g. two sheets of glass fiber filter, one sheet of cellulose filter and one sheet of polysulfone microporous membrane (
FIG. 1
of EP 785430 A1)
Another blood filter unit composed of a holder body and a cap was also developed. The holder body consists of a plasma receiver located on the upper side and a filter chamber located on the underside. The filter material put in the filter chamber is composed of six sheets of glass fiber filter and one sheet of polysulfone microporous membrane (Example 1 of EP 785012A1).
Incidentally, after drawing blood, fibrins gradually deposit to coagulate blood cells in whole blood samples, and as a result, agglutinates are formed, and serum is separated. Thereupon, serum can be obtained by sucking serum portion after agglutinates are formed.
While repeating analysis of the serum samples, the inventors found that, there is a dispersion of analytical results due to the destruction of blood cells caused by pressing agglutinates upon sucking the serum.
SUMMARY OF THE INVENTION
Accordingly, an object of the invention is to provide a method of preparing a serum sample from whole blood without destroying blood cells, and thereby, of obtaining highly reliable analytical values.
The inventors investigated eagerly in order to achieve the above object, and found that, there is a critical value between the insertion speed of a serum suction nozzle into a vessel and a suction pressure, and a blood serum sample can be obtained without destruction of blood cells by sucking the blood serum which keeping the sucktion pressure under the critical value.
Thus, the present invention provides a method of separating serum portion from whole blood which comprises inserting a suction nozzle provided with an agglutinate stopper at the lower and into whole blood wherein fibrins deposited placed in a vessel at an insertion speed of 30 cm/sec or less, and keeping the suction pressure of the suction nozzle at 400 mm Hg or less.


REFERENCES:
patent: 4477575 (1984-10-01), Vogel et al.
patent: 4810394 (1989-03-01), Masuda
patent: 5139685 (1992-08-01), de Castro et al.
patent: 5423989 (1995-06-01), Allen et al.
patent: 5876605 (1999-03-01), Kitajima et al.
patent: 5979669 (1999-11-01), Kitajima et al.
patent: 5996811 (1999-12-01), Kitajima et al.
patent: 6045699 (2000-04-01), Yazawa et al.
patent: 0 785 012 (1997-07-01), None
patent: 0 785 430 (1997-07-01), None
patent: WO 97/29369 (1997-08-01), None

Affiliated with

Also associated with

Rating

Method of separating serum from whole blood does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of separating serum from whole blood, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of separating serum from whole blood will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2470347