What effect can uneven pressure have on a blood smear?

• A. Create stripes
• B. Create bands
• C. Spots on the smear
• D. No effect

Answer: (B)

During smear preparation, applying pressure evenly is essential for a uniform distribution of cells. If pressure is uneven, cells are pushed more in some areas, creating a band of higher cell density where the slide was pressed harder. This banding artifact makes the smear thicker in that region and thinner elsewhere, which can distort cell morphology and lead to inaccurate counts in that area. Other issues like stripes or spots point to different problems (staining, drying, or contamination), but the hallmark effect of uneven pressure is this distinct band of cells across the smear.