The Knott's concentration technique in parasitology is specifically used to demonstrate:

• A Oocysts of Cryptosporidium in stool specimens
• B Microfilariae in peripheral blood with species identification by sheath staining ✓
• C Malarial parasites in thick blood film
• D Cysts of Entamoeba histolytica in fresh stool

Explanation

The Knott's concentration technique involves lysis of red blood cells with 2% formalin followed by centrifugation, concentrating microfilariae in the sediment for microscopic examination. It is particularly useful when microfilarial density is low, enabling species identification: Wuchereria bancrofti microfilariae have a sheath staining pink with Giemsa; Brugia malayi has a sheathed microfilaria with staining and characteristic terminal nuclei; Loa loa microfilariae are unsheathed with specific nuclear patterns. Thick blood film is the standard malaria diagnostic test; Knott's technique is specifically for filarial species.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.