A method of operating a biopsy device includes inserting a sampling probe having a first component and a second component into a biological tissue mass, the first component having a sample chamber and a side port that opens to the sample chamber, and the second component having a side opening; generating a vacuum in the sample chamber during a first drive interval; rotating at least one of the first component and the second component of the sampling probe during a second drive interval until the side port of the first component and the side opening of the second component are in radial alignment; and rotating at least one of the first component and the second component of the sampling probe during a third drive interval to sever tissue drawn by vacuum into the sample chamber to deposit a tissue sample in the sample chamber.