X-Nico

unusual facts about Gram stain



Alcian blue stain

Alcians blue carries Phthalocyanine one of the most highly colored chromophores yet known with a molar extinction of 120,000 i.e. AB is detectable at half the molar concentration of popular dyes like toluidine blue, tryarylmethanes (e.g. pararosaniline and the analogous Schiff bases used in PAS stain, Crystal violet in Gram stain) etc.

Septic arthritis

Diagnosis is by aspiration (giving a turbid, non-viscous fluid), Gram stain and culture of fluid from the joint, as well as tell-tale signs in laboratory testing (such as a highly elevated neutrophils (approx. 90%), ESR or CRP).


see also