This publication contains four detailed technical papers on CO2 isotopes, CH4 isotopes, N2O isotopes, and air extraction from ice cores for isotope measurements. They are intended for both experienced users and novices. The main focus of the contributions is to provide sufficient technical details and numerical data on the operating parameters used to minimize the trial-and-error phase. Special reference is given to issues of quality control and calibration, as these are highly relevant to the comparability of data between laboratories.