Blood separation device comprising a filter and a capillary flow pathway exiting the filter

• US 4,753,776 A
• Filed: 10/29/1986
• Issued: 06/28/1988
• Est. Priority Date: 10/29/1986
• Status: Expired due to Term

• Current Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Original Assignee: Biotrack, Inc. (Novartis Ag)
• Inventors: Gibbons, Ian, Hillman, Robert S.
• Primary Examiner(s): HRUSKOCI, PETER A
• Application Number:
  US06/924,633
• Time in Patent Office: 608 Days
• Field of Search: 422/58, 422/101, 210/503, 210/505, 210/508, 210/509, 210/651, 210/702, 210/451, 435/2, 436/69, 436/177, 436/178
• US Class Current: 422/535
• CPC Class Codes: B01D 2239/1216 Pore size
• CPC Class Codes: B01D 2239/1233 Fibre diameter
• CPC Class Codes: B01D 2239/125 Size distribution
• CPC Class Codes: B01D 39/2017 the material being filamentary or fibrous
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: B01L 2300/0681 Filter
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 3/502753 characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation separation in general B01D; microapparatus for analysis using electrophoresis G01N27/44791; sample preparation G01N1/28
• CPC Class Codes: G01N 33/491 by separating the blood components G01N15/05 takes precedence

Abstract

A method for separating plasma from red blood cells and a device utilizing the method in which a low-pressure filter is interposed in a pathway between an inlet port and a reaction area. The sole driving force for the movement of plasma from the filter to the reaction area is capillary force provided by a tubular capillary. The filter is selected from glass microfiber filters of specified characteristics, which can operate in the absence of agglutinins, and filters capable of separating agglutinated red cells from a plasma, which require the use of an agglutinin.

Claims

1. In a clinical diagnostic device comprising a housing having a fluid inlet port, a vented reaction area, and a capillary pathway connecting said inlet port and said reaction area and in which the driving force for the movement of liquid through said capillary pathway arises from capillary pressure, an improvement which comprises:

a low-pressure filter interposed in said pathway, wherein said filter is selected from the group consisting of binderless glass microfiber filters having a particle size retention in the range from about 1 μ

m to about 3 μ

m, a flow path of from about 0.5 to about 0.5 mm, and a density in the range from about 0.10 to 0.30 g/cm³ and comprises glass fibers having diameters essentially all in the range of from 0.10 to 4.0 μ

m with at least 60% of the fibers having diameters in the range of from 0.10 to 1.23 μ

m, wherein said device contains no agglutinin for red blood cells, whereby whole blood applied to said inlet port is separated into plasma and red blood cells by said low-pressure filter.

2. The device of claim 1, wherein said filter consists essentially of borosilicate glass fibers.

3. The device of claim 2, wherein said filter has a thickness of 0.50 to 0.80 nm, a particle size retention of from about 2.3 to 3.0 μ

m, and comprises glass fibers having diameters distributed over said range of from 0.10 to 1.23 μ

m so that 3 or 4 equal divisions of said range each contains a number of fibers varying by no more than 10 number percent.