This document is a standard operating procedure (SOP) for the haematology lab, detailing the process for estimating complete blood count (CBC) using the Erba H560 autoanalyzer. It outlines responsibilities of technical staff, required materials, and step-by-step procedures for sample analysis and machine maintenance. The SOP is authored by Attuluri Vamsi Kumar and approved by Prof. (Dr.) Ranjay Kumar Chaudary, effective from April 1, 2023.