A picking instrument for picking biological samples, such as microbial samples, includes a picking pin having a distal tip and three degrees-of-freedom and configured to move in x, y, and z directions. The picking instrument also includes a loading platform comprising a first area and a second area, the first area configured to accommodate and secure a microfabricated chip including a plurality of microwells. The picking pin is programmatically controlled to pick a sample contained in one or more selected microwells of the microfabricated chip and then transfer the sample to a predetermined location at the destination sample holder. Methods of operating the picking instrument, including calibrating the coordinates of the selected microwell(s) relative to a location of the picking pin, are also provided.