Method and apparatus for inoculating and streaking a medium in a plate

An apparatus for automatically inoculating and streaking a medium in a plate, the streaking using a streaking applicator having a line of resiliently and flexibly supported spaced apart contact surfaces, the apparatus including:

• (a) an inoculating and streaking station including:
• a predetermined plate work position having a notional action line fixed in two dimensions (x, y);
• and
• a rotatable platform;
• (b) a sensor mounted relative to the notional action line and arranged to locate, prior to inoculation and within a sensing region of the notional action line, the surface of the medium in a plate positioned in the plate work position to thereby determine a surface positional reference in a third dimension (z) indicative of the height of the surface of the medium in that plate and to determine, prior to inoculation, an action line in three dimension (x, y, z) across the surface of the medium in the plate;
• (c) a pipette robot system configured to move in two dimensions along the notional action line and in a third dimension to dispense inoculum, from a desired height relative to the action line, along the action line of the plate located in the plate work position;
• and
• (d) a streaking robot system configured to move the streaking applicator such that its line of spaced apart contact surfaces contacts at least the inoculum dispensed along the action line of the plate located in the plate work position, prior to rotation of the plate by the rotatable platform;
• and
• (e) an alarm configured to be activated if the surface positional reference (z) is determined to be above an upper detection limit or below a lower detection limit.