Cell concentration techniques include all of the following, except?

BHU NO - 2015

Pathology & Genetics

Medium

Appeared in: BHU NO - 2015

Explanation

Filtration is the correct answer because it is the only technique listed that does not use centrifugal force as its primary mechanism.
It works by physically trapping cells on a membrane based on size, while the other three options rely on separating cells based on density using a centrifuge.
Although filtration is a valid cell concentration method, its different working principle makes it the exception in this group.

Option A: Centrifugation is a fundamental and widely used cell concentration technique that uses centrifugal force to pellet cells. It is the basis for other methods like cytospin and cell block preparation.
Option B: Cytospin (cytocentrifugation) is a specialized application of centrifugation designed to create a monolayer of cells on a slide for cytological examination. It is a very common cell concentration technique.
Option C: Cell block preparation is a standard technique in cytology that begins with centrifuging a fluid specimen to concentrate the cells into a pellet, which is then processed for histological examination.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Principles of cell concentration techniques in cytology as background academic context rather than a clinical decision trigger.
Understanding these techniques helps nurses appreciate the importance of proper specimen handling. For example, a sample for cell block needs sufficient volume, and all samples must be transported promptly to prevent cell degradation, which affects all concentration methods.
The choice of technique depends on the clinical question and sample type. Filtration might be requested for CSF to rule out meningitis or malignancy, while a cell block from pleural fluid might be needed to diagnose cancer and perform further molecular tests.
What if? If a fluid sample (e.g., pleural fluid) is clotted upon arrival at the lab, it becomes very difficult to perform any of these concentration techniques effectively. This is why collecting the sample in a tube with the correct anticoagulant (like heparin) is a critical nursing responsibility.

How to Approach the Question

First, read the question carefully and identify the keyword 'except'. This means you are looking for the option that does not fit with the others.
Analyze the four options: Centrifugation, Cytospin, Cell block preparation, and Filtration.
Identify the common principle or category that links most of the options. In this case, think about the physical mechanism behind each technique.
Recognize that Centrifugation, Cytospin, and Cell block preparation all rely on centrifugal force to separate and concentrate cells.
Identify that Filtration uses a different mechanism—a physical barrier or sieve—to trap cells.
Conclude that Filtration is the exception because its mechanism is different from the other three, even though it is also a cell concentration technique.

Concept Tested & Keywords

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E6 PATHOLOGY QUICK REVIEWBased on Harsh Mohan Textbook of PATHOLOGY p. 77-79