Why buy? Just think of squeezing a chunk of lemon over your helping of haddock and drool into a small beaker. Remove bubbles by wiping the surface of the collected liquid with the edge of a piece of filter paper. Incubate for 30 minutes at 37C, just the same as for 0.1% malt diastase.
Saliva also contains RNase, but this doesn't matter because RNA is not stained by PAS or by other methods for staining glycogen. For a cheap source of RNase you can heat the collected saliva (80C for 10 minutes) to inactivate diastase and any other enzymes. Cool and centrifuge. Use the supernatant at 37C for 1 hour. Some references. Bradbury S (1956) Human saliva as a convenient source of ribonuclease. Quart. J. Microsc. Sci. 97: 323-327. (Free PDF available at https://jcs.biologists.org/content/s3-97/39/323.short). Brown, GG (1978) An Introduction to Histotechnology. New York: Appleton-Century-Crofts. pp. 302 (diastase) & 292 (ribonuclease). Drury RAB, Wallington EA (1967) Carleton's Histological Technique. 4th ed. Oxford University Press, Oxford. pp.163-164 (ribonuclease) & 208 (diastase). John Kiernan Dept of Anatomy & Cell Biology University of Western Ontario, London, Canada = = = ________________________________ From: Paula via Histonet <histonet@lists.utsouthwestern.edu> Sent: 26 November 2019 12:16 To: histonet@lists.utsouthwestern.edu <histonet@lists.utsouthwestern.edu> Subject: [Histonet] Diastase Hello, We've been using STATLabs Diastase for our PAS with diastase digestion but they have a backorder until January. Can anyone recommend an alternative from other vendors? Thank you in advance, Paula _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
