This results in the appearance of a distinct, brilliant "apple-green" color against a dark background. This specific apple. Many pathologists use Congo red to make a diagnosis of amyloid and state the common opinion that in polarized light, Congo red-stained amyloid shows apple-green birefringence, sometimes called.
Like most people working on amyloid, Colombat et al.1 report that Congo red-stained amyloid shows "green birefringence" or "apple-green birefringence," although their figures (5b, 6b, 7b, and 7d-f) show various colors, and in at least two (7e and 7f), green is difficult to see. We wrote to Kidney International in 2012 to point out a similar discrepancy between so-called "apple. Congo Red stain was performed to further evaluate the deposits, which shows red-orange positive staining under non-polarized light (Figure 4A and 4B).
With polarization, the deposits show "apple green" birefringence, confirming the presence of amyloid within the liver (Figure 4C and 4D). It is commonly thought that CR-stained amyloid has an orange-red appearance under light microscopy and apple-green birefringence under polarised light during in vitro investigations and in vivo histological studies using tissue sections [9, 147]. This particular color, resulting from the interaction of light with the gem's chemical composition and crystal structure, creates a visually striking effect that is both unique and aesthetically pleasing.
Gemstones exhibiting apple green birefringence possess a distinctive charm, setting them apart from their counterparts. When stained with Congo red and observed under polarized light, amyloid has a characteristic "apple green" birefringence as seen here in deposits around small arteries and within the cortex of the adrenal gland of a patient with multiple myeloma and excessive light chain production (AL amyloid). Most people seem convinced that the appropriate description of the properties of Congo red-stained amyloid is 'apple-green (or green) birefringence', although only 20% of images show pure green, 47.
The idea that green, and only green, is essential for the diagnosis of amyloid has persisted almost universally, and virtually all mentions of Congo red‐stained amyloid say that it just shows "green birefringence" or "apple‐green birefringence.". In the diagnosis of amyloidosis using Congo red staining, the apple-green birefringence observed under crossed Nicols has been considered the gold standard for over fifty years. However, a variety.
