High quality, continuous throughput, tissue processing

• US 20040004075A1
• Filed: 03/27/2003
• Published: 01/08/2004
• Est. Priority Date: 08/20/1997
• Status: Active Grant

• Current Assignee: University of Miami
• Original Assignee: Ervin Essenfeld, The University of Miami Harold Essenfeld
• Inventors: Essenfeld, Ervin, Essenfeld, Harold, Morales, Azorides
• Granted Patent: US 7,547,538 B2
• Time in Patent Office: Days
• US Class Current: 219/679
• CPC Class Codes: B01L 9/50 Clamping means, tongs in general F16B2/06
• CPC Class Codes: G01N 1/06 providing a thin slice, e.g. microtome
• CPC Class Codes: G01N 1/30 Staining; Impregnating ; Fixation; Dehydration; Multistep processes for preparing samples of tissue, cell or nucleic acid material and the like for analysis
• CPC Class Codes: G01N 1/312 for samples mounted on planar substrates
• CPC Class Codes: G01N 1/36 Embedding or analogous mounting of samples
• CPC Class Codes: G01N 1/44 Sample treatment involving radiation, e.g. heat
• CPC Class Codes: G01N 2001/305 Fixative compositions
• CPC Class Codes: G01N 2001/315 Basket-type carriers for tissues

Abstract

A process and apparatus for rapid, continuous flow histological processing of tissues is disclosed. The steps of fixation, dehydration, clearing and impregnation are performed in less than one hour; this allows a pathologist to evaluate samples shortly after receipt, perhaps while the patient is still in the operating room. Rapid and continuous processing is accomplished by decreasing the thickness of tissue sections, use of nonaqueous solutions composed of admixtures of solutions, solution exchange at elevated temperature and with agitation, and impregnation under vacuum pressure. The patient in surgery is thus provided with point-of-care surgical pathology.

Claims

1. A tissue specimen, or tissue section thereof, wherein the tissue specimen has been fixed and dehydrated in a series of non-aqueous solutions;

and then impregnated in a series of paraffin solutions.

2. The tissue specimen, or tissue section thereof, of claim 1 which has been fixed and dehydrated with heating by microwave energy.

3. The tissue specimen, or tissue section thereof, of claim 1 which has been impregnated under less than atmospheric pressure.

4. The tissue specimen, or tissue section thereof, of claim 1 which has been further defatted.

5. A tissue specimen, or tissue section thereof, wherein the tissue specimen has been hardened in a series of non-aqueous solutions with heating by microwave energy, and then impregnated in a series of paraffin solutions under less than atmospheric pressure.

6. A solution for hardening tissue, wherein the solution comprises a ketone and an alcohol, and the volume ratio of alcohol to ketone is from about 1:

1 to about 6;

1.

7. The solution of claim 6, wherein the volume ratio between alcohol and ketone is from about 1:

1 to about 3;

1.

8. The solution of claim 6 which further comprises surfactant.

9. The solution of claim 6 which further comprises mineral oil.

10. The solution of claim 6, wherein the solution comprises about 40% acetone, about 40% isopropyl alcohol, and about 20% low molecular weight polyethylene glycol by volume;

wherein low molecular weight for polyethylene glycol is average molecular weight of about 300.

11. The solution of claim 6, wherein the solution comprises about 10% acetone, about 60% isopropyl alcohol, and about 30% low molecular weight polyethylene glycol by volume;

wherein low molecular weight for polyethylene glycol is average molecular weight of about 300.

12. The solution of claim 6, wherein the solution comprises about 25% acetone, about 55% isopropyl alcohol, and about 20% mineral oil.

13. A specimen jar containing at least the solution of claim 6, and having at least one tissue cassette which may be immersed in the solution.

14. A solution for impregnating tissue, wherein the solution comprises mineral oil and paraffin, and the solution has been degassed.

15. The solution of claim 14, wherein the solution comprises about 30% mineral oil and about 70% paraffin.

16. An apparatus for continuous processing of tissue specimens comprising:

(a) a microwave processor unit which (i) fixes and dehydrates tissue specimens with a non-aqueous solution in a first vessel, (ii) agitates the non-aqueous solution, and (iii) heats the non-aqueous solution with microwave energy to produce processed tissue specimens; and

a first source for the non-aqueous solution which is fluidly coupled to the first vessel; and

(b) an impregnator unit which (i) impregnates processed tissue specimens with a wax solution in a second vessel and (ii) heats the wax solution under less than atmospheric pressure to produce processed and impregnated tissue specimens; and

a second source for the wax solution which is fluidly coupled to the second vessel.

17. The apparatus of claim 16, wherein processing of a subsequent tissue specimen is initiated before impregnation of an earlier tissue specimen has been completed.

18. The apparatus of claim 16, wherein the non-aqueous solution is comprised of an admixture of a ketone and an alcohol, and the volume ratio between alcohol and ketone is from about 1:

1 to about 3;

1.

19. The apparatus of claim 18, wherein the non-aqueous solution comprises about 25% acetone, about 55% isopropyl alcohol, and about 20% mineral oil.

20. The apparatus of claim 16, wherein a tissue specimen is fixed, dehydrated and impregnated in a total time of less than about two hours.

21. An apparatus for hardening and impregnating a tissue specimen comprising:

(a) a microwave unit which hardens the tissue specimen with a non-aqueous solution in a first vessel, and heats with microwave energy and agitates the non-aqueous solution in the first vessel;

wherein the non-aqueous solution in the first vessel is comprised of a ketone and an alcohol; and

(b) a vacuum unit which impregnates the hardened tissue specimen with a wax solution in a second vessel, and heats under less than atmospheric pressure the non-aqueous solution in the second vessel;

wherein the wax solution in the third vessel is comprised of paraffin wax; and

wherein tissue specimens are sequentially transferred into the first vessel and then into the second vessel.

22. The apparatus of claim 21, wherein hardening of a subsequent, not hardened tissue specimen is initiated in the microwave unit before impregnation of an earlier, hardened tissue specimen in the vacuum unit has been completed.

23. The apparatus of claim 21, wherein the volume ratio between alcohol and ketone is from about 1:

1 to about 3;

1.

24. The apparatus of claim 23, wherein the non-aqueous solution comprises about 25% acetone, about 55% isopropyl alcohol, and about 20% mineral oil.

25. The apparatus of claim 21, wherein the tissue specimen is hardened and impregnated in a total time of less than about two hours.