For instructions and further information, please go to Publications.

If you have questions that are not answered here, please contact us.

Q. What colors are most preferred? Which color is best?

A. We sell nearly equal quantities of all 7 colors and it appears one person likes blue, another likes green, another yellow, etc. This in part may be personal preference and in part is a result of differences in the local histochemical processing. There is no best color. The best color for you is the one that adheres best in your lab and which you find most easily distinguishable. Why does one person wear a red shirt and another a blue shirt? To some degree, these are color preferences. The same exist in the Davidson Marking System^® dyes. top

Q. Why do some colors stick better than others?

A. We don't know the answer to this. Some colors stick better in one lab and other colors better in another lab. While on paper, all histochemical processing is similar, there are some differences from one lab to the next. top

Q. What is the best method for obtaining maximum tissue dye adhesion?

A. The best is to receive the tissue fresh, blot free the excess fluids and then apply the dye. Shake or stir the bottom with the applicator and apply a small amount of dye with the cotton tipped end or with the wooden stick end to the tissue margin. The key is to let the dye slowly bond with the tissue. This requires time – 3 to 5 minutes is recommended. Oxidative and reductive chemicals do not improve the bonding nor does blow drying or assisted drying. The excess dye is then blotted away and the tissue processed. The same can be done with formalin preserved tissue. The process is identical. The dye adherence is excellent. It is just not quite equal to that obtained with fresh tissue. On the Instructions page, there are further suggestions for aiding the dyes in adhering to fatty tissues. top

Q. What is the difference between using the dyes for margins and using the dyes for orientation?

A. The dyes applied in the classic fashion for margins are applied to the perimeter of the surgical specimen before it is cut or sectioned or otherwise altered. The dye adheres to the periphery and once the sectioning is complete, anyplace where dye is located is a tissue margin. Many tumor margins today are not examined in the perpendicular fashion, but in the tangential fashion as originally described by Frederick Mohs. In these applications, anything on the slides represents tumor at the margin. The dyes are applied in such a way that they maintain tissue orientation. The typical orientations are superior, inferior, medial, lateral, right, left, etc. While there are numerous paradigms for the application of orientation markers, the most conventional is to section the tissue and to then apply the marking dyes. The package insert shows a typical application. Also, see the Instructions page. top

Q. Why is the instruction clear to NOT mark the living patient?

A. Under absolutely no circumstances can these dyes ever be applied to the patient. The dyes have been designed to adhere for life and any dye placed in the patient will remain for life. In addition, some of the dyes have been mixed with potentially poisonous chemicals. Although it might seem a brilliant idea to mark the patient and the specimen - the marking in the patient will remain six months, six years and 60 years later. The dyes are not manufactured under sterile conditions – another reason they should be used only on excised tissue specimens. top

Q: How might I go about diluting the dyes?

A. We do not recommend that the dyes be diluted as dilution would jeopardize the adherence quality of the product. It has been suggested by some of our customers that dilution with water at very small ratios is adequate without affecting the quality to a large degree. Once the product has been diluted, we cannot guarantee it's performance quality. top

Q. Does storage temperature affect the quality of the dyes?

A. It is not recommended that the dyes be frozen as some of the dyes (particularly the red and the black) are less adherent after they have been frozen. Comfortable room temperature is the best climate for the dyes. top

Q. What is the shelf life of the Davidson Marking System dyes?

A. The dyes have a long shelf life, provided the lids are kept on tightly. If the lids are left off during lab procedures, the dyes may thicken due to evaporation. top

If you have questions that have not been answered here, please contact us.