Day: January 29, 2012

Sunday, 29 January 2012

08:51 – We should finish the manuscript today, with two days to spare. Barbara is cleaning house this morning and then heading over to her parents’ house for lunch. We’ll shoot the final images this afternoon.

While I was doing laundry yesterday I had a few minutes to spare so I decided to make up the eosin Y stain for the biology kits. Eosin Y stain sold by most lab supply vendors can be anything from 0.2% to 1% eosin in either water or alcohol. Normally, the only other component is a preservative to prevent mold growth, usually a pinch of thymol or a few drops of chloroform per liter. But I’d been doing some research, and it seems that acidifying the stain with 1% or so acetic acid gives much better results.

So I dissolved 5 grams of eosin Y in nearly a liter of distilled water. It formed a very dark red solution that was so intensely-colored it was opaque even holding the bottle up to a strong light. I added 10 mL of glacial acetic acid and was surprised to see a distinct color change to almost orange. I’ll have to do a comparison test with the acidified eosin Y against neutral aqueous and alcoholic eosin Y before I use this for kits, but I suspect it’ll work very well.

// ------------------------------------------------------------------------------- // end of file // -------------------------------------------------------------------------------