Replica plating

For transforming S.pombe using drug selection, cells must first be plated onto rich media agar plates without selection and allowed to grow into a lawn before being transferred to a plate containing the appropriate drug. This is done by replica plating using a stamp and velveteen squares.

Contents

1. Procedure
2. Notes
3. References

1. Procedure

1. In sterile conditions place an autoclaved velveteen square over the stamp and hold in place with the stamp ring.
2. Place the master plate onto the stamp and press down firmly on the whole plate being careful not to twist so as not to spread out individual colonies.
3. After removing the master plate, place a fresh agar plate (with drug selection) onto the stamp, again pressing firmly and avoiding any rotation of the plate. Take care not to press too hard as you may split the agar or push cells around on the plate which can result in colonies that are merged.

2. Notes

One master plate can be used to transfer cells to at least 3 or 4 plates before all cells are removed from the velveteen. If doing several replicas of a master plate, you can use a non selective plate as a final replica to check that cells are indeed being transferred onto each previous plate.

3. References

Video of replica plating demonstration