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von Kossa staining – what light source to use
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von Kossa staining – what light source to use


Can anyone out there who performs Von Kossa staining provide me with any guidelines or suggestions for the light source to use for the Silver nitrate activation? Is a standard handheld black light strong enough or does it need to be a UV sanitizing strength light if using UV versus incandescent bulb exposure?

Answer 1.

I can't answer your question about UV light as I've never tried it except with incandescent lights. However, I do know that you could use natural sunlight as well to develop the silver color change.

Debbie Siena, HT(ASCP)QIHC Director of Scientific Affairs

Answer 2.

A handheld light of any kind isn't really suitable because you would have to hold it over the slides for 15 to 60 minutes, according to which variant of the von Kossa method you plan to use (see Lillie & Fullmer 1976 Histopathologic Technic. 4th ed. pp 539-541).

An anglepoise lamp with an old-fashioned 100W bulb is OK, and so is a sunny windowsill. Silver salts absorb at the blue end of the spectrum, so a fluorescent light should be more efficient than an incandescent bulb. If no bright light source is available, it's possible to chemically reduce the silver phosphate and/or carbonate to black colloidal silver, with a traditional photographic developer. The method of Rungby et al.1993 may be better than other post-reduction methods (

I never tried it, but Rungby's paper has collected 104 citations, which is very good for a paper in our field.

The von Kossa technique is simply explained in my Histological and Histochemical Methods textbook, 5th edn (2015). The book costs less than 1ml of any antibody. Enough said!

John John A. Kiernan, Emeritus, Anatomy & Cell Biology, University of Western Ontario London, Canada

Answer 3.

I use a 60 watt bulb and it works fine.

Bernice Frederick

Answer 4.

I have used a UV light like the ones for indoor plants and one that is in the fume hood for disinfection. Both proved successful.


Answer 5.

We've used the UV light for the hood disinfectant, as well as just taken a break out in the sunshine. Both worked just fine.

Terri L. Braud, HT(ASCP) HNL Laboratories for Holy Redeemer Hospital 1648 Huntingdon Pike Meadowbrook, PA 19046

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