This document provides an overview of immunophenotyping techniques used at Dr. Soetomo Hospital in Surabaya, Indonesia. It discusses the importance of immunophenotyping for distinguishing between ALL and AML, identifying cell lineages, assessing treatment response, and detecting minimal residual disease. The document outlines sample staining protocols, common antibody panels, and several case studies demonstrating how immunophenotyping was used to classify different types of acute leukemia at the hospital.