Cell Count & Differential Count Flashcards
What is the primary cell count routinely performed on CSF specimens?
- LEUKOCYTE/WHITE BLOOD CELL COUNT.
When are RBC counts typically determined in CSF specimens?
- Usually determined only when a TRAUMATIC TAP
- Has occurred and a correction for leukocytes or protein is desired.
Why is it important to perform cell counts on CSF specimens ASAP (as soon as possible)?
- RBCs disintegrate within 1 hour
- WBCs decrease by 40% after 2 hours, which can affect the accuracy of the results.
What is the significance of RBC disintegration within 1 hour in CSF specimens?
- This fact is significant because it emphasizes the need for timely analysis to obtain accurate cell count results.
After how long does the WBC count decrease by 40% in CSF specimens?
- After 2 hours
- Highlighting the importance of prompt analysis to maintain the reliability of the results.
What is pleocytosis in the context of cell count?
- Pleocytosis refers to an increase in the number of cells in the cerebrospinal fluid (CSF).
What are the normal cell count values for adults, and which type of cells are predominant in adults?
- The normal cell count values for adults are 0-5 cells/uL
- And the predominant cells in adults are lymphocytes.
What are the normal cell count values for neonates, and which type of cells are predominant in neonates?
- 0-30 cells/uL
- The predominant cells in neonates are monocytes, which are the largest white blood cells and precursor cells.
What are two methods commonly used for cell counting?
- Manual counting using a Neubauer Counting Chamber
- And automated counting using Automated Cell Counters.
What is the quality control requirement for cell counting?
- Should agree with automated cell counting results within a margin of ±25% as a quality control measure.
How can you ensure the accuracy of cell counting results?
- It’s important to validate manual cell counts against automated counts
- Ensure they fall within the specified ±25% range for quality control.
What does a significant RBC count in the Total Cell Count indicate?
- Suggests that a traumatic tap has occurred
- And is needed for the correction of WBC Count & CSF Protein Results.
Why is the RBC count important in this context?
- It helps distinguish between a traumatic tap and other conditions
- And allows for accurate adjustments to WBC Count and CSF Protein Results.
When can clear specimens be counted undiluted for Total Cell Count?
- Clear specimens may be counted undiluted for Total Cell Count.
What is used as a diluent for Total Cell Count when needed, and what should be used for milky appearances in CSF?
- Normal Saline Solution (NSS) is used as a diluent, and it’s also used for milky appearances in CSF.
What type of pipettes should be used for Total Cell Count, and why?
- Calibrated, automatic pipettes (MICROPIPETTE)
- Should be used for Total Cell Count to ensure accuracy and precision.
How should cells be counted when performing Total Cell Count?
- Cells should be counted in the four corner squares and the center square of the specimen.
Why is it necessary to lyse red blood cells (RBC) prior to counting white blood cells (WBC)?
- Lysing RBCs is necessary to ensure accurate WBC counts by eliminating interference from red blood cells.
What is the diluent used for lysing RBCs in total cell count?
- A 3% glacial acetic acid solution is used as the diluent to lyse RBCs in total cell count.
Is it possible to enhance the cell count process with Methylene Blue?
- Yes, Methylene Blue can be added to the diluting fluid to enhance the cell count process.
What should be done if dilution is not required for cell counting?
- If dilution is not necessary
- The pipette should be rinsed with the diluting fluid prior to aspiration to maintain accuracy in the cell count.
What is the standard calculation formula used for CSF cell counts?
- Used for CSF cell counts follows the same method as that used for blood cell counts.
How many larger corner squares and larger center square are used for counting CSF cells?
- Four larger corner squares and the larger center square are used for counting CSF cells.
What are the dimensions of the counting area for CSF cells?
- Has dimensions of 3mm length X 3mm width, divided into 9 large squares.
How is the volume of CSF cells calculated?
- By multiplying the area of 1 square (1mm²) by the depth (0.1mm)
- Which is the distance between the coverslip and the counter chamber. This gives a volume of 0.1mm³.
What is the formula for calculating the volume of CSF cells?
- VOLUME = (Area in mm²) X (Depth in mm) = 0.1mm³.
Why are calculations made to correct for WBCs in CSF due to a traumatic tap?
- Calculations are made to account for WBCs introduced in CSF during a traumatic tap to obtain an accurate WBC count.
How is the Correct WBC Count calculated?
- Determined by subtracting the WBCs added during the traumatic tap from the actual WBC count in the cerebrospinal fluid.
What does it indicate if peripheral WBC and RBC counts are normal?
- If peripheral white blood cell (WBC) and red blood cell (RBC) counts are within the normal range
How can you correct for contamination in a cerebrospinal fluid (CSF) sample when white blood cells (WBC) have been added?
- Use the formula: WBC added = WBC Blood x RBC CSF / RBC Blood.
What is the shortcut method for calculating the white blood cell count (WBC) in cerebrospinal fluid (CSF) based on the number of red blood cells (RBCs)?
- Subtract 1 WBC for every 700 RBCs present in the CSF
- For example, if there are 1,400 RBCs/uL and 100 WBCs/uL, the calculated WBC count is 98 WBCs/uL.
