Analytical test device with substrate having oriented through going channels and improved methods and apparatus for using same

• US 6,383,748 B1
• Filed: 09/14/1999
• Issued: 05/07/2002
• Est. Priority Date: 09/14/1999
• Status: Expired due to Term

• Current Assignee: PamGene B.V. (VitrOmics Healthcare Holding BV)
• Original Assignee: PamGene B.V. (VitrOmics Healthcare Holding BV)
• Inventors: Papen, Roeland F., Carpay, Wilhemus M.
• Primary Examiner(s): NGUYEN, BAO THUY L
• Application Number:
  US09/395,514
• Time in Patent Office: 966 Days
• Field of Search: 435/6, 435/970, 435/973, 435/287.1, 435/287.2, 436/518, 436/538, 436/528, 436/165, 436/810, 436/805, 436/530, 422/58, 422/57, 422/101
• US Class Current: 435/6.11
• CPC Class Codes: B01F 2215/0409 Relationships between different variables defining features or parameters of the apparatus or process
• CPC Class Codes: B01F 25/451 characterised by means for moving the materials to be mixed or the mixture
• CPC Class Codes: B01F 25/4523 the components being pressed through sieves, screens or meshes which obstruct the whole diameter of the tube
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01F 33/3021 the components to be mixed being combined in a single independent droplet, e.g. these droplets being divided by a non-miscible fluid or consisting of independent droplets
• CPC Class Codes: B01J 2219/00891 Feeding or evacuation
• CPC Class Codes: B01L 2300/069 Absorbents; Gels to retain a fluid
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: B01L 3/5025 for parallel transport of multiple samples
• CPC Class Codes: B01L 3/50857 using arrays or bundles of open capillaries for holding samples
• CPC Class Codes: G01N 2035/106 by sucking and blowing
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 435/973 Simultaneous determination of more than one analyte
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

The present invention is directed to methods for analyzing one or more fluid samples for the presence, amount or identity of one or more analytes optionally present in said samples, which uses a device having one or more round wells with a fixed diameter, the wells exposing a substrate of a specific thickness, whereby the substrate has oriented through going channels, in the area of the substrate exposed in the well is provided with at least one binding substance specific for a least one of said analytes. Using the device the sample fluid is forced to pass through the channels in the substrate from the upper side of the substrate to the lower side of the substrate and back at least one time, under conditions that are favorable to a reaction between any analyte present in the sample and the binding substances.

Claims

1. A method for analyzing one or more fluid samples for the presence, amount or identity of one or more analytes present in said samples, comprising the steps of:

(a) providing a device comprising one or more round wells with a fixed diameter, said wells exposing a substrate having a thickness, said substrate having oriented through going channels, and an area of the substrate exposed in the well being provided with at least one binding substance specific for at least one of said analytes;

(b) adding an amount of sample fluid to one or more of the wells of the device;

(c) generating an alternating flow through the substrate in the wells by applying an alternating pressure difference over the substrate in the wells, said alternating pressure difference being lower than a capillary pressure of the channels in the substrate, whereby a liquid volume of the sample is forced to pass through the channels in the substrate from an upper side of the substrate to a lower side of the substrate and back at least one time, so as to allow for a reaction between analyte present in the sample and the binding substance(s);

(d) reading any signal generated in any of the wells; and

(e) determining from said signal(s) the presence, amount and/or identity of said one or more analytes.

2. The method according to claim 1, wherein the substrate is washed prior to reading the signal.

3. The method according to claim 1, wherein the amount of added sample fluid is calculated on the basis of at least one of a dimension or a material characteristic of the wells, the substrate and the sample fluid.

4. The method according to claim 3, wherein the amount of sample fluid added to each well does not exceed V_max2, and V_max2 is calculated according to the following equation:

$V_{m<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{x2}}=\mathrm{\pi <br><br>}·<br><br>R_{\mathrm{well}}·<br><br>\left(\frac{2·<br><br>\mathrm{\gamma <br><br>}}{\mathrm{\rho <br><br>}·<br><br>g}+R_{\mathrm{well}}·<br><br>d\right)$

wherein

R_well=a radius of the well

d=a depth of the well

γ

=a surface tension of the sample liquid

ρ

=specific mass of the sample liquid

g=gravitational acceleration.

5. The method according to claim 4, wherein a volume of the sample does not exceed the smallest value of V_max2.

6. The method according to claim 1, wherein the amount of sample fluid added to each well does not exceed V_max, and V_max is calculated according to the following equation:

$V_{m<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>x}=\mathrm{\pi <br><br>}·<br><br>R_{\mathrm{well}}^2·<br><br>\left(d+\frac{R_{\mathrm{well}}}{3·<br><br>{\sin }_{\mathrm{\vartheta <br><br>}}^3}<br><br>{\left(1-\cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\vartheta <br><br>}\right)}^2<br><br>\left(2+\cos <br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\vartheta <br><br>}\right)\right)$

wherein

R_well=a radius of the well

d=a depth of the well

∂

=a contact angle between the sample fluid and a surface of the substrate.

7. The method according to claims 6, wherein a volume of the sample does not exceed the smallest value of V_max.

8. The method according to claim 1, whereby a downward flow through the channels of the substrate is created by applying an underpressure underneath the device, and said underpressure is maintained until all sample fluid has passed through the channels of the substrate and has formed a drop that hangs underneath the substrate of the well, then an upward flow through the channels of the substrate is created by raising the underpressure to a sufficient overpressure, and said overpressure is maintained until all fluid has passed through the channels again in an upward direction and has formed a drop on an upper surface of the substrate, and repeating these steps for as many times as necessary to assure an optimal contact between the analyte(s) and the binding substances).

9. The method according to claim 1, wherein the reaction between the analyte and the binding substance is continuously monitored during alternation of the flow through the substrate by reading the signal from a top surface of the substrate.

10. The method according to claim 9, wherein the signal is read whenever the fluid has passed through the substrate and hangs as a drop underneath the substrate.

11. The method of claim 1, wherein the channels of the substrate are provided with a first binding substance in at least one area of the substrate, wherein the substrate is placed between a top cover and a bottom cover and the wells are formed by holes made on corresponding locations in both the top cover and bottom cover.

12. The method according to claim 11, which is preformed with an apparatus for the automated performance for one or more assays, and which comprises (a) means for addition of a controlled amount of a fluid to at least one of the wells of the device;

and (b) means for applying and/or maintaining for a sufficient amount of time a controlled pressure difference over the substrate in each of the wells.