Dear List, I have a question regarding the use of biological versus technical replicates in a microarray experiment: I have two groups of samples, before treatment and after treatment. For some samples I have biological replicates for before and after treatment (bucal swabs collected with a small brush) For some patients one of my biological replicates usually after treatment exibited a high degree of RNA degradation, but one sample remains OK. Therefore I was wondering if I could mix biological replicates for some patients (before and after) and for others biological replicates for before treatment and technical replicates for after treatment. If anybody would care to comment it would be quite welcome. Regards, -- Marcos B. Pinho Programa de Engenharia Química - PEQ Laboratório de Engenharia de Cultivos Celulares- LECC Universidade Federal do Rio de Janeiro - UFRJ Instituto Nacional de Câncer - INCA Rio de Janeiro - Brasil [[alternative HTML version deleted]]