Lyophilizing of liquid drops having arbitrary edges and application thereof to microarrays of biological reagents

• US 6,605,438 B1
• Filed: 03/26/2001
• Issued: 08/12/2003
• Est. Priority Date: 03/26/2001
• Status: Expired due to Fees

• Current Assignee: Louis Dischler
• Original Assignee: Louis Dischler
• Inventors: Dischler, Louis
• Primary Examiner(s): FORMAN, BETTY J
• Application Number:
  US09/817,652
• Time in Patent Office: 869 Days
• Field of Search: 435/6, 435/174, 435/287.2, 435/283.1, 435/7.1, 530/300, 530/350, 536/23.1, 422/68.1, 422/50, 422/58, 422/101, 436/518
• US Class Current: 506/16
• CPC Class Codes: B01J 19/0046 Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays synthesis methods per se C40B50/00
• CPC Class Codes: C07H 21/02 with ribosyl as saccharide radical
• CPC Class Codes: G01N 1/40 Concentrating samples
• CPC Class Codes: G01N 1/42 Low-temperature sample treatment, e.g. cryofixation
• CPC Class Codes: G01N 2001/4027 evaporation leaving a concentrated sample

Abstract

The disclosure relates to the stabilization of a fluid drop comprising a liquid solvent and solute, so that upon drying of the solvent, the solute is not preferentially concentrated at the edges of the residual spot, and more particularly relates to the preparation of microarrays containing biological reagents.

Claims

1. A method of preparing spots on a substrate surface, comprising the steps of:

(a) providing a first fluid liquid drop comprising a random edge in contact with a substantially flat portion of the substrate surface, wherein said first fluid liquid drop comprises a first solvent liquid and a first solute;

(b) cooling the substrate surface prior to step “

a”

, so that said first solvent liquid is frozen by contact with the cooled substrate surface; and

(c) subsequently subliming substantially all of said first solvent liquid to form a first spot comprising a first concentration gradient of said first solute, wherein said first concentration gradient is substantially unmodified by evaporation of said first solvent liquid from said first fluid liquid drop.

2. A method of preparing spots on a substrate surface, as recited in claim 1, further comprising the step of:

prior to step “

c”

, providing at least a second fluid liquid drop comprising a random edge in contact with a substantially flat portion of the substrate surface, wherein said second fluid liquid drop comprises a second solvent liquid and a second solute, and wherein said second solvent liquid is frozen by contact with the cooled substrate surface.

3. A method of preparing spots on a substrate surface, as recited in claim 2, wherein said second solute is different from said first solute.

4. A method of preparing spots on a substrate surface, as recited in claim 2, wherein said second solvent liquid is different from said first solvent liquid.

5. A method of preparing spots on a substrate surface, as recited in claim 4, wherein said second solute is different from said first solute.

6. A method of preparing spots on a substrate surface, as recited in claim 1, wherein said first solute is a dissolved solid.

7. A method of preparing spots on a substrate surface, as recited in claim 1, wherein said first solute is an amino acid.

8. A method of preparing spots on a substrate surface, as recited in claim 1, wherein said first solute comprises a nucleic acid.

9. A method of preparing spots on a substrate surface, as recited in claim 8, wherein said nucleic acid is cDNA.

10. A method of preparing spots on a substrate surface, as recited in claim 1, wherein said solute is a liquid.

11. A method of preparing spots on a substrate surface, as recited in claim 1, wherein said first solvent liquid is water.

12. A method of preparing spots on a substrate surface, as recited in claim 1, wherein said first solute is dispersed in said first solvent liquid.

13. A method of preparing spots on a substrate surface, as recited in claim 1, further comprising, after said subliming substantially all of said first solvent liquid, the steps of:

(d) subsequent to freezing said first fluid drop, providing a second fluid drop comprising a second liquid solvent and a second solute so as to at least partially cover the first drop or spot;

(e) cooling the substrate surface prior to step “

d”

, so that said second fluid drop is frozen by contact with the cooled substrate surface; and

(f) subsequently subliming substantially all of said second liquid.

14. A method of preparing an array of dried spots of solute on a substrate surface, comprising the steps of:

(a) providing an array of spaced fluid drops on the substrate surface, wherein each of said spaced fluid drops comprises a solvent liquid and a variable solute, and a random edge in contact with a substantially flat portion of the substrate surface, and wherein said random edge of each of said spaced fluid drops is not coincident with any raised surface geometry on the substrate surface;

(b) cooling the substrate surface prior to step “

a”

, so that said array of spaced fluid drops is frozen by contact with the cooled substrate surface; and

(c) subsequently subliming substantially all of said first solvent liquid from said array of spaced fluid drops with substantially no evaporation, thereby preparing said array of dried spots.