An optimized FAIRE procedure for low cell numbers in yeast.

We report an optimised low-input FAIRE-seq (Formaldehyde-Assisted Isolation of Regulatory Elements) procedure to assay chromatin accessibility from yeast colonies. Sensitivity, specificity and reproducibility of the scaled-down method are comparable to that of regular, higher input amounts, assayed over a 100-fold range. The method enables epigenetic analysis of chromatin structure to be assayed without the need for liquid culture, thus opening the possibility to study wild yeasts that form colonies, or those can be isolated in sufficient amounts in situ, from environmental samples. Overall design: FAIRE assays of 8 samples: 4 FAIRE samples based on varying amounts of cells (4 mg, 20 mg, 100 mg and 500 mg) and 4 corresponding input DNA samples. 3 biological replicates per sample. Please note that each processed narrowPeak file was generated from each sample pair (i.e. FAIRE and input, e.g. *F-R* and *I-R* samples) and is linked to the corresponding FAIRE sample record.