1.Introduction: Biotechnology and Genetically Modified Crops -- 2.Seed Testing -- Purity and Low-Level Presence (LLP) -- 3.Grain Supply Chain Testing -- Import and Export -- 4.Principles of Nucleic Acid-Based Detection Methods -- 5.Method Validation: DNA Based Detection Methods -- 6.Principles of Protein Detection Methods -- 7.Method Validation: Protein Detection Methods -- 8.Sources and Use of Reference Materials -- 9.Seed and Grain Sampling -- 10.Plant and Field Analysis -- 11.Testing Laboratory Design and Management -- 12.International Standards -- 13.Analytical Strategy and Interpretation of Results -- 14.Detection of Gene-Edited Products -- 15.Future Perspectives and Challenges.