Help! Mouse Pee On Negatives!

[John Layton]

Nightmare scenario here...with a number of 5x7 negative sleeves having been evidently peed on by a mouse, with the sleeves then having wicked some of this pee in to "infect" about a dozen or so images, about half of which are "keepers."

So what I've done so far is to very carefully cut the sleeves apart and discard them, then run the infected negatives through a series of four trays...two of plain water and two with Photo-Flo - in nitrile-gloved hands and very gently rubbing the areas affected.

The cleaned up negatives, when viewed in oblique light, do show a bit of difference in the affected areas - but this is very subtle. When viewed on a lightbox, I can see absolutely nothing indicating that they'd been affected.

Question: my guess is that our slightly alkaline deep-well water would tend to help neutralize what must have been some rather acidic pee...but have I gone far enough? Should I run these negatives through a tray of (alkaline) TF-5 fixing bath, then rewash them?

[Michael R]

TF-5 is not alkaline.

[John Layton]

Mind fart about TF-5...as I'd switched over from the (slightly alkaline) TF-4 last year.

[Drew Wiley]

TF-4 seems to be the Neanderthal species approaching extinction due to the presence of a more efficient species. Just like Neanderthals, it tended to settle down too much, and was resistant to mixing. Once I tried TF5, there was no going back. No more guck stuck to the bottom of the bottle, yet the same excellent result, with no change in protocol.

I have no experience with mouse pee. The entire exterior perimeter of the darkroom building is patrolled by cats.

[xkaes]

Urine is usually very close to PH 7 -- unless this mouse has a kidney disease. Why do you assume it is acidic? Coincidentally, I tested mine last week and it was 6.8. You probably don't have to worry about the PH , but it might have other stuff in it you don't want on your negatives. So distilled water should be fine for cleaning.

[phdgent]

Just a question about this (not an advise nor a statement) but, in this particular situation, shouldn't these 'infected' negatives be washed with a kind of disinfecting (household-) soap and well rinsed thereafter?
Soap is alkalic, mainly made with KOH or NaOH in it, could it then neutralise the effects of urine, and kill the bacteria that are in the urine and can go om living in the emulsion's gelatine?

Just wondering...

[John Layton]

As for mouse pee being acidic...according to my online sources it is certainly very acidic. But then again...these are online sources - and we know how that can go!

Very interesting point about the possibility of bacteria feeding on my negatives (pause here for an Edvard Munch Scream...) - and that maybe I should be cleaning them with something strongly disinfective...but then I'd worry about that also in terms of potential negative damage.

So...I think I'll just go my regimen of two plain (slightly alkaline) water baths, followed by two with Photo-Flo, and then keep my fingers crossed!

[xkaes]

Urine normally has very low levels of bacteria, and a PH close to 7. It's not as bad as many assume.

[JMO]

The vicissitudes of living with nature. The urine will have had various manner of salts, minerals and proteins (etc.) in it, so your Photo Flo or even a film cleaner product that is designed to remove fingerprints (mostly composed of greasy or oily sebum) should help to remove whatever was suspended and excreted in that mouse pee....

[MrFujicaman]

John, as to killing off germs, get a pint of Everclear from the liquor store and pour some in a baggie and shake the negs with it.