Under which objective is sediment examined in Modified Knott's technique?

Under which objective is sediment examined in Modified Knott's technique?

• A. 40x
• B. 100x
• C. 10x
• D. 400x

Answer: (B)

In Modified Knott's technique, you’re looking for microfilariae concentrated in the sediment, so you need enough magnification to see their slender, wormlike shape and key features that distinguish them from debris. The 100x objective (often with oil immersion) provides a level of detail that reveals the overall morphology, including length, curvature, and the presence of the sheath and characteristic nuclear pattern, which helps confirm identification. Lower magnifications won’t resolve these small but important details, making it harder to distinguish parasites from debris. Very high magnification like 400x narrows the field of view too much for efficient screening and doesn’t add practical diagnostic value for routine detection.

In Modified Knott's technique, you’re looking for microfilariae concentrated in the sediment, so you need enough magnification to see their slender, wormlike shape and key features that distinguish them from debris. The 100x objective (often with oil immersion) provides a level of detail that reveals the overall morphology, including length, curvature, and the presence of the sheath and characteristic nuclear pattern, which helps confirm identification.

Lower magnifications won’t resolve these small but important details, making it harder to distinguish parasites from debris. Very high magnification like 400x narrows the field of view too much for efficient screening and doesn’t add practical diagnostic value for routine detection.