Preserving Cell Integrity: Techniques to Minimize Cell Lysis in Veterinary Blood Smears
Cell lysis can significantly impact the quality and diagnostic utility of a blood smear. Even minor handling errors or inconsistent techniques can cause cells to rupture, resulting in a smear that is difficult to interpret under the microscope. Understanding the factors that contribute to lysis and making simple adjustments to the smearing process can help preserve cell integrity, ensuring that the prepared slides offer clear, reliable data for evaluation.
To minimize cell lysis during the blood smear preparation process, it’s important to handle the blood sample and smear technique as gently and consistently as possible. Here are several adjustments you can make:
Avoid Excessive Pressure:
Applying too much force with the spreader slide can crush fragile cells and lead to lysis.
Use light, steady pressure rather than pressing down hard. The motion should feel more like “gliding” rather than “pressing.”
Maintain a Smooth Spreading Motion:
Jerky, uneven movements can cause mechanical stress on cells, leading to rupture.
A continuous, steady motion across the slide ensures the cells experience minimal mechanical disruption.
Check the Angle of the Spreader Slide:
A very steep angle may create more pressure at the point of contact, increasing the risk of lysis.
Adjusting to a slightly lower angle can reduce shear forces, allowing the cells to spread more gently.
Adjusting the angle to the viscosity of the blood is ideal. Learn how to do this here.
Monitor Blood Drop Volume:
Using a drop that is too large may lead to overcrowding and increased mechanical friction.
A smaller, well-mixed drop of about 2-3 uL can be more evenly spread, reducing the likelihood of cell damage.
Use Fresh Blood Samples:
Older or improperly stored samples may have compromised cell membranes, making them more prone to lysis during smearing.
Whenever possible, prepare smears promptly after collection.
Check Slide and Spreader Cleanliness:
Any debris or rough edges on the slide or spreader can physically damage cells.
Ensure both slides are clean and smooth before beginning the smear.
By paying close attention to the angle, pressure, and motion of the spreading technique, as well as ensuring the blood sample and slides are in optimal condition, you can greatly reduce the risk of cell lysis. These careful adjustments not only improve the appearance of the smear but also enhance its diagnostic accuracy, enabling more precise identification and analysis of blood cells.
References
Jain, N. C. (1993). Essentials of Veterinary Hematology. Lea & Febiger.
Stockham, S. L., & Scott, M. A. (2008). Fundamentals of Veterinary Clinical Pathology (2nd ed.). Wiley-Blackwell.
Thrall, M. A., Weiser, G., Allison, R. W., & Campbell, T. W. (2012). Veterinary Hematology and Clinical Chemistry (2nd ed.). Wiley-Blackwell.
