JFC Solution: FAQ

What is the composition of the one-step dehydrating/clearing solution (JFC)?

JFC solution is a patented product consisting of a mixture of ethanol, isopropanol, and a long chain hydrocarbon.

Can I use other reagents instead of JFC for the histoprocessing?

Yes. The PATHOS and RHS microwave processors are not closed systems for reagents. They were developed to allow the user to choose the proprietary JFC solution, or ethanol-isopropanol, or a combined use of ethanol-JFC, for use as follows:

Ethanol-Isopropanol-Wax
Ethanol-isopropanol protocol is recommended as the standard method for histoprocessing small to medium-large biopsies, provided that the fat content of the tissue blocks is kept to a minimum. It is a very cost-effective protocol for general histoprocessing. This is the recommended method for processing of renal biopsies.

Ethanol-JFC-Wax
Ethanol-JFC is for use with tissues where overnight fixation of tissue is uncertain, and for partially fixed tissues. In this instance, the ethanol acts as a post-fixative step, since JFC is not a fixative. This protocol is especially suited for routine use and for very fatty tissues, such as breast. The ethanol step will extend the reuse life of the JFC.

JFC-Wax
JFC solution is strongly recommended for tissues known to be well fixed, generally at least overnight, and is of major benefit when dealing with tissues that contain high lipid content, such as larger pieces of breast and brain.

How many times can I re-use the JFC solution?

It can be used at least twice, and possibly further, depending on the quantity and size of samples processed, and whether a preceding microwave step in ethanol is used. It is essential, if you intend to reuse again, to make sure that the container is covered to prevent loss of reagent vapors, and to prevent absorption of atmospheric moisture.

Can I dispose of JFC solution down the drain?

No. Due to the properties of the hydrocarbon (not miscible with water in pure form), it may accumulate and therefore increase risks of flammability in the drainage system. Dispose of JFC solution in accordance with disposal instructions from your local environmental protection agency.

Can I recycle the JFC solution?

No, as the ratio of the individual components is not disclosed. However, if the recycling unit is of a high standard, the individual components may be used for other applications (e.g., ethanol use in staining machines).

What is the temperature of the JFC solution used?

68°C.

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FineFIX: FAQ

General

What is FineFIX?

FineFIX concentrate is a water-based additive. When added to ethanol, it creates a formalin-free fixative (the concentrate is not the actual fixative) for use in routine histology and molecular analysis. Its patented mix of chemical additives is reconstituted into a working solution by the addition of ethanol.

How does FineFIX compare with Formalin fixation?

This histology quality is such that it does not interfere with diagnosis, just as with formalin-fixed tissues.

What is the safety and toxicity level of the FineFIX working solution?

FineFIX is much less toxic than formalin. The allowable exposure limit of FineFIX (when reconstituted into a working solution by the addition of ethanol) is 1,000 ppm, versus a limit of 0.75 ppm for conventional Formalin (10%).

As ethanol is the predominant chemical in the FineFIX working solution and is highly flammable, safety procedures must be in accordance with the Material Safety Data Sheet (MSDS) for ethanol.

How does FineFIX compare with Ethanol fixation?

FineFIX is not subject to the disadvantages normally associated with Ethanol fixation (shrinkage, vacuolization, and pyknotic nuclei).

Results

Which tissue types has FineFIX been tested on, and for how long?

The fixative has been in routine use for all specimen types in typical surgical pathology labs for continuous periods of up to two years. The quality of histology for tissues fixed in these labs shows absolutely the same appearance as that of the original samples.

What is the effect of FineFIX on preservation of antigens and the subsequent Immunohistochemical technique?

As FineFIX is not a cross-linking fixative, there is no need for aggressive epitope retrieval. It is recommended not to exceed a temperature of 100°C, for a duration of 5–15 minutes, during retrieval procedures. The exact timing will depend on the type of antigen under evaluation and the immunohistochemical method performed by the laboratory.

What are the benefits of FineFIX for molecular techniques?

Improved recovery of DNA and RNA compared to formalin-fixed tissues.

Usage

How do you prepare the FineFIX working solution?

The working solution is prepared by adding 720 ml of reagent grade or pure ethanol to 280 ml of FineFIX concentrate, followed by brief mixing.

How many times can I re-use FineFIX?

FineFIX working solution is to be used in the same way as formalin, which is a once-only use when transporting specimens. Due to the potential for carry-over contamination between tissue samples, re-use is not recommended, especially if the solution is badly discolored (saturated) with contaminants.

Can I use FineFIX in a conventional histoprocessor?

Yes. It can be used as a replacement for formalin when used in the first containers of the conventional processor. It provides the added benefit of simultaneous fixation, dehydration, and fat removal.

Can I use FineFIX in a microwave histoprocessor?

Yes. Microwaves can be used to accelerate tissue fixation, provided that the temperature does not exceed 50°C. It is therefore important to use a microwave unit that has automatic temperature control.

Are there any changes required to histochemical staining methods?

No. Histochemical stains are performed using the same protocols that are used on formalin-fixed, paraffin-embedded tissue.

Is FineFIX working solution compatible with other tissue processing fluids (for example: ethanol, acetone, xylene, isopropanol, and J.F.C.) and with common decalcifying agents?

Yes.

Storage & Disposal

How do I store the FineFIX concentrate?

It can be stored in a cool, well-ventilated place, and does not require treatment as a flammable product.

How do I store and dispose of FineFIX working solution?

As alcohol is a major part of the solution, it must be treated and stored as a flammable product, as you do now for the alcohol used in your tissue processors. For disposal, ethanol can be recycled using a solvent recycler, and the remaining residue can be disposed of. In both instances, the storage and disposal will be according to the MSDS for ethanol and local, state, or federal regulations.

Does FineFIX concentrate and/or working solution have an expiration date?

Experience has shown both solution formats still continue to work well beyond 2 years.

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ProWAVE Solution: FAQ

Are there cost savings using ProWave?

Yes.

• The most expensive thing in a laboratory is tech time. With Prowave you save money and time because you are only using one tank for Prowave instead of the normal Ethanol and Isopropanol tanks. ProWave is a one step reagent.
• By using ProWave, there is no need to change out the gallon containers weekly as would be necessary with conventional techniques.
• The paraffin may be reused, if desired, as the ProWave evaporates out of the paraffin. If JFC is currently being used, although it is also a one step reagent, it is also a long chain hydrocarbon. As a long chain hydrocarbon, it will contaminate paraffin in approx. 3 months.

Is ProWave a safer alternative to conventional reagents?

Yes.

• ProWave is a safer alternative because there is less exposure to hazardous chemicals.
• The volume of chemical usage decreases significantly when combining Microwave processing and Prowave

Instructions on how to use ProWave in an existing RHS.

• The newer RHS units have ProWave protocols already in them. If they are not visible on the touch screen, they can be activated by going into the Service Screen/Software Settings and clicking on ProWave.
• The older units (smaller touch screen units:- terminal M) do not have Prowave as an option. These users should use the existing JFC/Wax protocols. The time and temperature for Prowave is the same as JFC.

Instructions on how to use ProWave in an existing Pathos

• The Pathos unit must have the software updated in order for ProWave to be used successfully. This should be done by a Milestone service rep. It is important that ProWave not be used in a Pathos until this update is completed.
• Upon receiving the software upgrade, it is possible to follow the ProWave protocols on the instrument screen.
• In Reagent Management, the customer should change tank 4 from Ethanol to Prowave. Prowave is placed in the #4 In Use Tank by performing an Automatic Ethanol Alcohol Exchange.