Preparation of total RNA from a very small wheat embryo suitable for differential display

A simple method was developed for extracting total RNA from a single mature wheat seed embryo, which is very small and hard. Guanidine thiocyanate and chloroform were employed and the grinding of the samples was performed in a microcentrifuge tube with a plastic pestle. A “jacket” of liquid nitrogen and simplified procedures were applied to ensure the thorough grinding of the embryo tissue and to minimise the loss of samples. These measures substantially increased the recovery of total RNA in the extraction process. Reliable differential display was successfully achieved with the total RNA after DNase treatment and reverse transcription. This method makes it viable to study gene expression and gene regulation in a single wheat seed embryo. It may also give researchers the ability to analyse mRNAs in tissues or organs which were previously too small for RNA isolation using conventional procedures.