Are gout crystals negative birefringence?

They are positively birefringent, appearing blue when aligned parallel with the slow axis of the compensator and yellow when perpendicular.

What are crystals associated with pseudogout?

Pseudogout has been linked to the presence of calcium pyrophosphate dihydrate crystals within the affected joint. These crystals become more numerous as people age, appearing in nearly half the population older than age 85.

What is birefringence microscopy?

Birefringence is formally defined as the double refraction of light in a transparent, molecularly ordered material, which is manifested by the existence of orientation-dependent differences in refractive index.

Is pseudo gout positively birefringent?

Pseudogout crystals (CPP) are rod-shaped with blunt ends and are positively birefringent. Thus, pseudogout crystals are blue when aligned parallel to the slow ray of the compensator and yellow when they are perpendicular. Crystals must be distinguished from birefringent cartilaginous or other debris.

What is the difference between gout and pseudogout?

In pseudogout, or CPPD, crystals of pyrophosphate dihydrate form in your joints causing pain. Gout, on the other hand, is caused by the formation of monosodium urate crystals due to high levels of uric acid. The crystals form around your joints, causing pain.

What are the crystals in gout?

Gout and pseudogout are the two most common crystal-induced arthropathies. Gout is caused by monosodium urate monohydrate crystals; pseudogout is caused by calcium pyrophosphate (CPP) crystals and is more accurately termed calcium pyrophosphate disease (CPPD).

What is birefringence and dichroism?

Birefringence: Property of some crystalline materials (e.g., calcite) where the anisotropy is exhibited as a change of refractive index between light rays vibrating in different planes. A subset of birefringence, when the anisotropy is wavelength dependent (a measure of dispersion), is called Dichroism.