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UND 363 P.A. Meth.
UND 363 Periodic Acid-Methenamine silver
Question | Answer |
---|---|
Purpose for Periodic Acid-Methanamine silver M'wave | best delineates basement membrane (used in detection of abnormalities of glomerular BM in KIDNEY) |
principle for Periodic Acid-Methanamine silver M'wave | periodic acid oxidize carbs of basement membrane which reduces aldehyde. The least aldehydes will be reduced w/ silver to visible metallic silver |
books principle for Periodic Acid-Methanamine silver M'wave | carbs of BM oxidized to aldehyde by Per. Acid. Aldehydes bind to silver ions from methen. silver and reduce silver to visible. Toned with gold chloride and unreduced silver removed with sodium thiosulfate |
fix for Periodic Acid-Methanamine silver M'wave | 10% NBF preferred, CANNOT use mercury containing fixatives. |
tech | ***2 microns**** |
QC for Periodic Acid-Methanamine silver M'wave | kidney as internal control, no other control is necessary |
reagents for Periodic Acid-Methanamine silver M'wave (in order) | periodic acid - oxidation, methanimine silver - silver impregnation, gold chloride - toning, sodium thiosulfate - remove unreduced silver, lt green - counterstain |
results | basement membrane - black, background - green |
why is m'wave used | give sharper stain of BM and less background staining |
why is temp critical | should be just below or approx. 95○C (each oven should be calibrated for appropriate time) |
what are some issues with this stain | very difficult to perform correctly, stopping silver staining too soon will result in uneven or interupted staining. too much counterstain will mask the silver. |