Methods and Compositions for Hematoxylin and Eosin Staining

Abstract

The present invention provide for solutions of a defined composition useful in a staining protocol, such as a hematoxylin and eosin staining protocol, when used at certain points of the staining protocol. The formulations of these defined solutions are such that carry-over of the solutions will not negatively impact, or preferably, will stabilize or favorably modify staining reagent solutions coming in contact with the solutions. In certain embodiments of the invention, solutions are buffered to maintain a specific pH that when carried-over—such as carried-over into hematoxylin—will not significantly influence the pH of the next staining reagent.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Patent Application No. 61 / 591,181 filed Jan. 26, 2012, which is incorporated herein by reference in its entirety.BACKGROUND[0002]The hematoxylin and eosin (“H and E”) staining technique is the most commonly used histological technique for the visualization of pathology in tissue specimens. A typical H and E staining system is composed of solutions comprising aluminum based hematoxylin, eosin, a differentiating solution, and a bluing agent. Hematoxylin is a natural dye that when complexed with aluminum ions produces a positively charged molecule that binds to deoxyribonucleic acid to produce a purple coloration of cell nuclei. Differentiation solutions typically are lightly acidic solutions that sharpen the contrast of the stained slide by removing excessive background staining from the tissue and slide. Bluing agents are solutions of a basic pH that when applied to stained specimens ...

AI Technical Summary

Benefits of technology

The patent text describes a method and kit for performing H and E staining, which is a common staining process used in histology laboratories. The invention aims to mitigate the negative effects of solution carry-over, which can lead to increased pH and background staining. The method and kit provide a consistent lifespan for all the reagents used, allowing for up to 2,000 or 2,700 slides to be processed before new reagents are substituted. The technical effects of the invention include improved staining quality, reduced waste of reagents, and improved efficiency of the staining process.

Problems solved by technology

While the batch format of staining is simple, economical, and relatively rapid, there are drawbacks with the technique.

The movement of racks carrying slides from one container to the next results in the carry-over of staining reagents or water.

Carry-over is undesirable because it may affect the functionality of the downstream staining reagents in several ways.

Carry-over and dilution can also affect the functionality of the staining reagent by changing the characteristics of the solvent and thus affecting such parameters such as pH and ionic strength of the solvent.

Finally, carry-over may introduce contaminants to the staining reagent.

Acting through these mechanisms, carry-over negatively impacts the performance, functionality, stability, predictability, and capacity of the staining system.

Although a single instance of carry-over may result in such negative impacts, the negative impacts of carry-over are especially problematic over the course of multiple staining runs as the negative impacts build or are amplified as the result of the cumulative effects of repeated carry-over.

Because of the negative effects of carry-over, the capacity or useful life of reagents in current staining systems is highly unpredictable.

Therefore, solutions in current systems are often changed at different rates, i.e., at different times. This adds complexity and inefficiency as staining is continually stopped to change just one or less than all of the solutions.

On the other hand, if all of the solutions are changed at once, some of them are discarded while still having useful capacity to process additional slides, and thus money is wasted.

However, unpredictability and loss of staining effectiveness due to carryover still remains a major unresolved problem.

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