Bisulfite-based tissue fixative

• US 5,432,056 A
• Filed: 11/15/1993
• Issued: 07/11/1995
• Est. Priority Date: 11/15/1993
• Status: Expired due to Term

• Current Assignee: Ventana Medical Systems Incorporated (Roche Holding AG)
• Original Assignee: Ventana Medical Systems Incorporated (Roche Holding AG)
• Inventors: Jones, Christine R., Klotz, Janis L., Hartman, Anthony L.
• Primary Examiner(s): CEPERLEY, MARY
• Application Number:
  US08/152,863
• Time in Patent Office: 603 Days
• Field of Search: 436/18, 436/826, 424/3, 435/7.21, 435/7.23, 435/1, 435/960, 435/961
• US Class Current: 435/7.21
• 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 2001/307 non-toxic, no Hg, no formaldehyde
• CPC Class Codes: G01N 2474/20 Immunohistochemistry assay
• CPC Class Codes: Y10S 435/962 Prevention or removal of interfering materials or reactants or other treatment to enhance results, e.g. determining or preventing nonspecific binding
• CPC Class Codes: Y10S 436/826 Additives, e.g. buffers, diluents, preservatives
• CPC Class Codes: Y10T 436/108331 Preservative, buffer, anticoagulant or diluent

Abstract

The present invention provides a bisulfite-based tissue fixative that improves morphology, antigen retention, and antigenicity. The fixative is suitable for use with sections of frozen tissue, cytology preparations (including touch preparations and blood smears) and other specimens used for immunohistochemical analysis. The fixative comprises an acidic buffer and a bisulfite salt in an effective amount for tissue fixation. In a preferred embodiment, the tissue fixative comprises a bisulfite salt in a concentration of from about 0.01 to about 0.25M, preferably, 0.02 to 0.25M, in an acidic buffer having a pH of from about 2 to about 6.

Claims

1. A tissue fixative comprising an acidic buffer having a pH of from about 4 to about 5 and, as the sole fixative agent, a bisulfite salt in a concentration of from about 20 mM to about 250 mM.

2. The tissue fixative of claim 1 wherein said bisulfite salt is present in a concentration of from about 20 mM to about 80 mM.

3. The tissue fixative of claim 1 wherein said bisulfite salt is sodium bisulfite.

4. The tissue fixative of claim 1 wherein said acidic buffer is selected from the group consisting of acetate buffer and citrate buffer.

5. The tissue fixative of claim 1 wherein said fixative consists essentially of 40 mm sodium bisulfite in 0.1 M acetate buffer having a pH of from about 4 to about 5.

6. A method of fixing tissue comprising contacting said tissue with a tissue fixative comprising an acidic buffer having a pH of from about 4 to about 5 and, as the sole fixative agent, a bisulfite salt in an effective amount for tissue fixation.

7. The method of claim 6 wherein said bisulfite salt is present in a concentration of from about 10 mM to about 250 mM.

8. The method of claim 6 wherein said tissue is selected from the group consisting of a frozen section, a cytological preparation, and a needle biopsy.

9. The method of claim 6 additionally comprising the step of contacting the tissue section with an antibody.