The following fixative is used to prepare tissue for electron microscopy

NEET PG NEET PG MCQs
#1
  1. The following fixative is used to prepare tissue for electron microscopy:

(A)B5

(😎 Glutaraldehyde

© Bouin’s fluid

(D) Zenker’s fluid

  1. A primary lesion caused by mycobacterium bacilli (tuberculosis) developed in the

lung of a previously uninfected individual is referred to as a:

(A) Ghon focus

(😎 Ghon complex

© Simon’s focus

(D) Koch complex

  1. Ans B

Glutaraldehyde is the classic fiXative for electronmicroscopy. Very small/thin

portions of tissue must be used as its penetrative abilities are poor. B5 and Zenker’s

fluids are mercury-based fixatives that are sometimes used for bone marrow and other

lymphoreticular specimens as they produce excellent nuclear detail. Bouin’s fluid has

traditionally been used for testicular biopsies and small lymph node biopsies, as it

also gives better nuclear detail than neutral buffered formalin. It has the additional

advantage that it colours tiny biopsies yellow and makes them easier to see and more

difficult to lose.

  1. Ans A

A primary lesion caused by mycobacterium bacilli (tuberculosis) developing in the

lung of a previously uninfected individual is called a Ghon focus. If it also involves

infection of surrounding lymph nodes, it is known as a Ghon complex. A Ghon’s

focus results from haematogenous seeding at the time of initial infection, is present at

the apex of the lung, contains viable organisms and serves as the source of

reactivation in approximately 10% of people.