Cytocentrifugation Methods for Specimen Concentration

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Questions and Answers

What is the recommended number of cells to count during cerebrospinal fluid analysis?

50 cells

100 cells

100 cells, classified in percentage (correct)

200 cells, classified in percentage

What is the primary benefit of adding 30% albumin to the conical chamber during cytocentrifugation?

Increases cellular distortion

Decreases cell yield

Has no effect on cell yield or cellular distortion

Increases cell yield and decreases cellular distortion (correct)

What is the typical composition of cerebrospinal fluid in adults?

80% lymphocytes and 20% monocytes

50% lymphocytes and 50% monocytes

30% lymphocytes and 70% monocytes

70% lymphocytes and 30% monocytes (correct)

What is the purpose of cytocentrifugation in cerebrospinal fluid analysis?

To concentrate the specimen Signup and view all the answers

What is the main advantage of cytocentrifugation in meningitis diagnosis?

It is highly sensitive Signup and view all the answers

What is the reversed proportion of lymphocytes and monocytes found in children's cerebrospinal fluid?

30% lymphocytes and 70% monocytes Signup and view all the answers

Why is it important to correct the WBC count in CSF analysis?

To account for contamination from blood Signup and view all the answers

What is the purpose of adding 3% glacial acetic acid to the diluting fluid?

To lyse RBCs prior to WBC count Signup and view all the answers

What is the purpose of performing a differential count on a stained smear?

To identify the type of WBCs present Signup and view all the answers

Why is it important to use a calibrated pipette when collecting CSF?

To ensure accurate measurements Signup and view all the answers

What is the purpose of rinsing the pipette with the diluting fluid prior to sucking?

To ensure equal distribution of cells in the chamber Signup and view all the answers

When is it necessary to correct the RBC count?

When a traumatic tap has occurred Signup and view all the answers

What is the primary cause of parasitic invasion of the CNS worldwide?

Fungal infections (primarily Coccidiodes immitis) Signup and view all the answers

What is the normal percentage of neutrophils in CSF with a normal WBC count?

Up to 7% Signup and view all the answers

What type of cells are seen in CSF following diagnostic procedures such as pneumoencephalography?

Clusters of uniform cells Signup and view all the answers

Which of the following is characterized by an autoimmune disorder where the myelin sheath is attacked?

Multiple sclerosis Signup and view all the answers

What is the significance of finding hemosiderin granules in CSF?

May be seen 2-4 hours after RBCs enter the CSF Signup and view all the answers

What is the primary function of laboratory personnel in regards to CSF analysis?

To differentiate between abnormal and normal cells Signup and view all the answers

Study Notes

Cell Counting and Classification

Count and classify 100 cells in percentage for cerebrospinal fluid (CSF) analysis.
Utilize methods for specimen concentration: sedimentation, filtration, centrifugation (5–10 minutes), and cytocentrifugation.

Specimen Preparation

In cytocentrifugation, add CSF (minimum 0.1 ml) and 30% albumin to a conical chamber.
30% albumin enhances cell yield and minimizes cellular distortion.

Cytocentrifugation Process

Cells are concentrated into a monolayer within a 6 mm diameter circle on the slide during centrifugation.
Cytocentrifugation is highly sensitive for cellular recovery.

White Blood Cell Recovery Chart

Chart shows the relationship between the number of white blood cells (WBCs) counted and total cells counted.
Example: 0 WBCs = 0 cells, 250 WBCs = 20 cells.

CSF Cellular Constituents

Normal CSF primarily contains lymphocytes and monocytes:
- Adults: 70% lymphocytes, 30% monocytes.
- Children: 30% lymphocytes, 70% monocytes.

Diagnostics

Examination of CSF aids in diagnosing types of meningitis and infections.
Automated electronic cell counters enhance accuracy, but manual counts should agree within ±25%.

Calculation of CSF Cell Counts

Formula: Cell count = number of cells counted × dilution factor.
Example calculation: A counting of 100 WBCs with a dilution factor results in a count of 5000 WBCs/mm³.

Counting Methods

Count RBCs in 1 large square and WBCs in 4 corner squares and center square.
Always lyse RBCs before counting WBCs; use 3% glacial acetic acid for this purpose.

Differential Cell Count

Performed on stained smears, differentiating between abnormal and normal cells.
Key leukocytes include neutrophils, eosinophils, lymphocytes, monocytes, and macrophages.

Notable Conditions and Changes

Neutrophil levels may increase in bacterial meningitis; early cases can have various white cells.
Different forms of meningitis (viral, tubercular, fungal) can show specific cellular profiles.
Parasitic CNS invasion is the most prevalent global cause.

Nonpathologically Significant Cells

Cells may appear post-diagnostic procedures and during neurosurgery; uniformly appear in clusters.
Includes choroidal, ependymal, and spindle cells from the choroid plexus lining.

Additional Cells in CSF

Ghost cells, hemosiderin granules, and hematoidin crystals may be present after hemorrhage.
Autoimmune disorders like multiple sclerosis can show all stages of leukocyte development within CSF.

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Description

This quiz covers the methods of specimen concentration, including sedimentation, filtration, centrifugation, and cytocentrifugation. Learn about the techniques used to increase cell yield and decrease cellular distortion. Test your knowledge of laboratory procedures and cellular analysis.