PROCESS AND APPARATUS FOR TESTING SUBSTANCES FOR POTENTIAL CARCINOGENICITY

• US 20120149058A1
• Filed: 03/19/2010
• Published: 06/14/2012
• Est. Priority Date: 03/20/2009
• Status: Active Grant

• Current Assignee: F Hoffmann-La Roche AG (Roche Holding AG)
• Original Assignee: F Hoffmann-La Roche AG (Roche Holding AG)
• Inventors: Voegelin, Dieter
• Granted Patent: US 9,778,277 B2
• Time in Patent Office: Days
• US Class Current: 435/39
• CPC Class Codes: G01N 35/028 having reaction cells in the form of microtitration plates
• CPC Class Codes: G01N 35/1067 for transfer to or from containers having different spacing

Abstract

An apparatus (2) for the automatic testing of substances for carcinogenicity comprises: a plate support (3) on which at least one micro-well plate (1) can be placed; a movable pipetting unit (4) comprising a predetermined number of pipettes (40); a number of containers (5) containing a liquid culture medium (50), the number of containers (5) corresponding to the number of pipettes (40) of the pipetting unit (4); a dish support (6) on which a corresponding number of dishes (60) can be placed, each having a bottom and an upstanding side wall (601); spinning means (63) for spinning the dishes (60); closing means (62) for placing a lid (600) on each of the dishes; transport means (64,65) for transporting the closed dishes (60) to an intermediate storage (8).

Claims

1. A process for automatically testing substances for potential carcinogenicity, the process comprising the steps of:

providing a plurality of substance/salmonella mixtures in the wells (10) of a micro-well plate (1);

moving a predetermined number of pipettes (40) towards the wells (10) of the micro-well plate (1);

intaking into the pipettes (40) a desired amount of the respective substance/salmonella mixtures contained in the wells (10) of the micro-well plates (1);

moving the pipettes (40) with the intaken substance/salmonella mixtures to a corresponding number of containers (5) containing a liquid culture medium (50);

intaking into the pipettes (40) a desired amount of liquid culture medium (50) and mixing it with the respective intaken substance/salmonella mixtures;

moving the pipettes (40) with the intaken substance/salmonella mixtures and culture medium to a corresponding number of dishes (60), each dish (60) having a bottom and an upstanding side wall (601) surrounding the bottom as well as a solid culture medium (61) arranged on the bottom of the dish (60);

dispensing the respective mixtures of substance/salmonella and culture medium from the pipettes (40) into the associated dishes (60);

spinning the dishes (60) to effect spin-coating of the solid culture medium (61) in the respective dish with the mixture of substance/salmonellaliquid culture medium dispensed into the said dish;

stopping spinning of the dishes (60) to allow the dispensed mixture to form a uniform layer of substance/salmonella and liquid culture medium on the entire surface of the solid culture medium (61) in the respective dish (60);

closing the dishes with respective lids (600);

incubating the closed dishes (60) for a predetermined time under predetermined conditions; and

counting the number of salmonella colonies in the dishes (60) so as to determine whether or not the substance is potentically cancerogenic.

2. The process according to claim 1, wherein the step of providing a plurality of substance/salmonella mixtures to be tested in the wells of a micro-well plate comprises:

preparing a predetermined number of different dilutions of each substance to be tested;

filling the different dilutions of the substances into different wells (10) of the micro-well plate (1);

admixing salmonella strains to the different dilutions of the respective substance to obtain substance/salmonella mixtures containing the substance to be tested in different dilutions;

and providing these different dilutions of the substance/salmonella mixtures in different wells (10) of the micro-well plate (1).

3. The process according to claim 2, wherein the step of providing a plurality of substance/salmonella mixtures further comprises adding liver enzymes in a liquid form to the different dilutions of each substance prior to admixing the salmonella strains.

4. The process according to claim 1, wherein the respective solid culture medium (61) arranged in the respective dish (60) is heated prior to dispensing the mixtures of substance/salmonella and culture medium from the pipettes (40) into the associated dishes (60).

5. The process according to claim 4, wherein the heating of the solid culture medium (61) arranged in the respective dish (60) is performed using IR-radiation.

6. The process according to claim 1, wherein the step of intaking into the pipettes (40) a desired amount of liquid culture medium (50) and mixing it with the respective intaken substance/salmonella mixtures comprises aspirating air into the pipettes (40) for performing the mixing of the intaken substance/salmonella mixtures with the liquid the culture medium (50).

7. An apparatus (2) for the automatic testing of substances for potential carcinogenicity, comprising:

a plate support (3) on which at least one micro-well plate (1) can be placed, the micro-well plate (1) comprising a plurality of substance/salmonella mixtures or substance/salmonella/liver enzymes mixtures in the respective wells (10) of the plate (1);

a movable pipetting unit (4) comprising a predetermined number of pipettes (40);

a number of containers (5) containing a liquid culture medium (50), the number of containers (5) corresponding to the number of pipettes (40) of the pipetting unit (4);

a dish support (6) on which a corresponding number of dishes (60) can be placed, each dish (60) having a bottom and an upstanding side wall (601) surrounding the bottom as well as a solid culture medium (61) arranged on the bottom of the dish (60);

spinning means (63) for spinning the dishes (60);

closing means (62) for placing a lid (600) on each of the dishes so as to close the respective dishes (60);

transport means (64,65) for transporting the closed dishes (60) to an intermediate storage (8) capable of collecting a plurality of closed dishes (60) so as to forward them to an incubator.

8. The apparatus according to claim 7, further comprising heating means (7) which are capable of being positioned above the respective solid culture medium (61) arranged in the respective dishes (60) on the dish support (6).

9. The apparatus according to claim 8, wherein the heating means (7) comprise a number of IR-heaters (70,71) corresponding to the number of dishes (60) that can be arranged on the dish support (6) at the same time.

10. The apparatus according to claim 7, wherein the pipettes (40) of the pipetting unit (4) are arranged at an inclination angle (α

,−

α

) relative to a normal to the plane of the plate support (3), with adjacently arranged pipettes (40) being arranged at opposite inclinations (α

,−

α

) relative to the normal.

11. The apparatus according to claim 10, wherein the angle (α

,−

α

) is in the range up to 10°

relative to the normal, and amounts in particular about 7.5°

relative to the normal.

12. The apparatus according to claim 7, wherein the pipetting unit (4) comprises spacing means (41) for laterally moving the pipettes (40) towards and away from one another.

13. The apparatus according to claim 12, wherein the spacing means (41) comprise a gear (410,411,412,413,414,415) with a fixed gear transmission ratio.

14. The apparatus according to claim 7, wherein the pipettes (40) are disposable pipettes (40).