Questions and answers

How is Deparaffinization done?

How is Deparaffinization done?

These procedures are performed prior to staining. Deparaffinization is to remove the paraffin penetrated into the tissue. After deparaffinization, xylene is removed with 100% ethanol. Then, slides are hydrated in a series of graded alcohols until water is used….⑪ Deparaffinization & hydration.

100% ethanol I Removal of xylene
100% ethanol III

What is Deparaffinization in staining?

Deparaffinization (removal of paraffin wax from tissues) and staining are the important steps in any histopathology and cytopathology laboratories. The station can be used for multi-purpose staining processes Eg: Deparaffinization, H&E, PAP staining and all other kinds of Histology and Cytology stains.

Why xylene is used for Deparaffinization?

Histologists are usually exposed to xylene during histoprocessing, deparaffinization, and clearing prior to coverslipping. [10] Worldwide, xylene is considered to be the most commonly used dewaxing and clearing agent as it renders tissue transparent and removes alcohols from tissues rapidly.

Is xylene used for Deparaffinization?

Xylene, a flammable and toxic organic solvent, is the only available solvent used to deparaffinize tissues prior to staining with Hematoxylin or eosin (H&E) staining. Xylene inhalation can affect the central nervous system causing headaches, nausea, vomiting and dizziness [2].

Can you leave slides in xylene?

You can leave slides in xylene overnight to get good clearing of any water. Coverslip slides using xylene-based PermountTM. Place a drop of Permount on the slide using a glass rod, taking care to leave no bubbles.

How do you rehydrate a slide?

Deparaffinize and rehydrate by immersing the slides through the following solutions/ wells:

  1. Xylene, three washes 5 minutes each.
  2. 100% Ethanol, two washes 10 minutes each.
  3. 95% Ethanol, two washes 10 minutes each.
  4. 70% Ethanol, two washes 10 minutes each.
  5. 50% Ethanol, two washes 10 minutes each.

What is regressive staining?

What is Regressive Staining? Regressive staining is a more rapid staining technique in which the tissue is deliberately over stained until the dye saturates all tissue components. Then the tissue is selectively de-stained until it reaches the correct endpoint. De-staining step is called differentiation.

Can you mix xylene with water?

Xylene evaporates and burns easily. Xylene does not mix well with water; however, it does mix with alcohol and many other chemicals.

What happens when you mix xylene and water?

Well xylene and water does not mix also. The mixing of the two has many bad results in processing and staining. If water is present in the xylenes during tissue processing then the tissues are more prone to “frying” become brittle. Then they must be dehydrated in 2 changes of 100% alcohol and possibly re-stained.

Why do you rehydrate tissue to stain?

For the staining of paraffin slides, it is essential to rehydrate your sections. Otherwise staining will be unpossible or uneven, since antibodies and other essential compounds solved in hydrous media will not be able to bind to a hydrophobic surface.