Filter arrangement using elution fluid and method for using the same

• US 11,073,450 B2
• Filed: 04/17/2018
• Issued: 07/27/2021
• Est. Priority Date: 02/05/2013
• Status: Active Grant

• Current Assignee: Pocared Diagnostics Ltd.
• Original Assignee: Pocared Diagnostics Ltd.
• Inventors: Ingber, Gal
• Primary Examiner(s): Orme, Patrick
• Application Number:
  US15/955,163
• Publication Number:
  US 20180266926A1
• Time in Patent Office: 1,197 Days
• 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 2300/0887 Laminated structure
• CPC Class Codes: B01L 2400/049 vacuum
• 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 1/34 Purifying; Cleaning processes or apparatus for extracting or separating nucleic acids from biological samples C12N15/1003
• CPC Class Codes: G01N 1/4077 by other techniques involving separation of suspended solids
• CPC Class Codes: G01N 2001/4088 filtration

Abstract

A filter arrangement with a top element and a bottom element and a filter element therebetween captures oversized particles on the upper surface of the filter element and tangentially rinses these particles using an elution fluid to provide a concentration of particles in a relatively low volume of fluid for further analysis. In an intermediate step, the particles captured by the filter may be rinsed with a rinsing fluid such as water to pass additional undersized particles through the filter, thereby providing a purer sample. To improve efficiency, check valves may be used for passageways with one-way flow. Additionally, a configuration of three-way stopcocks may also be utilized. Finally, a sandwich arrangement is possible, wherein a single bottom element is sandwiched between two opposing top elements.

Claims

1. Using a fluid/particle mixture and a filter element that captures over-sized particles and allows undersized particles to pass through, a method for separating the particles from a fluid/particle mixture using a flat filter element having an upper surface and an opposing lower surface, comprising the steps of:

a) filtering the fluid/particle mixture through the filter element so that the over-sized particles are deposited on an upper surface of the filter element;

b) tangentially rinsing the upper surface of the filter element with an elution fluid to displace the particles deposited upon the upper surface;

c) collecting the displaced particles and the elution fluid in a first collector to provide a first stage of filtering; and

d) repeating steps a) through b) with the collected displaced particles and elution fluid from the first collector to provide a second stage of filtering and collecting the displaced particles and the elution fluid in a second collector.

2. The method of claim 1, further including, after at least one step of filtering the fluid/particle mixture, the step of rinsing additional particles through the filter element with water.

3. The method of claim 1, wherein filtering the fluid/particle mixture through the filter element is done using suction in a direction from the top of the filter element to the bottom of the filter element.

4. The method according to claim 1, wherein the particles are bacteria.

5. The method according to claim 1, wherein the filter element is a polycarbonate-type filter element which is a surface filter.

6. The method according to claim 5, wherein the filter element has pores with openings approximately 0.4 microns wide.

7. The method according to claim 1, wherein the elution fluid is effervescent.

8. The method according to claim 1, wherein the elution fluid is made up of phosphate-buffered saline.

9. The method according to claim 1, wherein the elution fluid contains a foaming agent.

10. The method according to claim 9, wherein the foaming agent is effervescent.

11. The method according to claim 1, wherein the second stage of filtering occurs using a different segment of the filter element than the first stage of filtering.