Topic 2: Specimen transport, accessioning, and gross dissection

Why is formalin the standard fixitive?

It is inexpensive, validated for use, and tolerant

When is glutaraldehyde used to fix samples?

Preservation for PNS samples and electron microscopy

When is Bouin’s solution used to fix samples?

For trichrome staining or fixing + decalcifying samples

When is ethanol used to fix samples?

When uric acid demonstration is requried

When do we used fresh/frozen unfixed tissue?

For molecular diagnostics and it must be analyzed or frozen immediately

When do we use cold isotonic saline unfixed tissue?

Transporting muscle and kidney biopsies less than 1 hour transport

What is Michel’s Medium?

Solution that preserves tissue antigenicity for days

When is Michel’s Medium used?

Samples that are tested using immunofluorescent methods

What is RPMI?

A solution designed to support and maintain growth of human lymphocytes

When is RPMI used?

Lymphatic tissue for immunophenotyping when lymphoma is suspected

What are in toto specimens?

Specimens that can be submitted in its entirety without dissection

Which specimens can be submitted in toto?

Small skin biopsies, GI biopsy, needle core, uterine, vas deferens

What is a representative section?

Small portion of tissue used to represent the entire area

What is a standard section?

Section that is always collected during grossing`

What is the fixative of choice for skin biopsies?

10% neutral buffered formalin

What are the three standard skin biopsies collected?

Shave, punch, elliptical excision

What is a shave biopsy?

Only the uppermost layer (epidermis) is removed using a razore

What is a punch biopsy?

Circular core of skin is removed that includes the epidermis and large portion of the dermis

What is an elliptical incision?

A scalpel is used to made an incision to collect the epidermis, dermis, and subcutaneous tissue