Tuesday, November 07, 2006

I am an HISTOLOGIST: I seek to understand things.

Life is almost completely transparent. Histology has the goal of making it less transparent and hence more tractable. Why does 'transparent' mean obvious, easily understandable?

There are two parts to histology; fixatives and stains. Fixatives "freeze" the tissue by cross-linking proteins. Stains are dyes or inks, many borrowed from the textile industry. They work in sundry ways, but the idea is that each is only "sticky" to a certain substrate. I remember learning in O-Chem that even nitrile gloves are porous to some fluids, although latex is sufficient to stop them. And it turns out that the most useful glues and adhesives are those that are selectively sticky, not universally so. (The tape-stuck-on-the-hand syndrome). Antibodies are the most selectively-sticky glues, and in the past 30 years we figured out how to grab them with our dyes.

I wonder if any dyes ARE antibodies? A good candidate to investigate this would be tannins.

(Toluidine blue was used to dye the cervical connective in Manduca Sexta).

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