Method for reading machine-readable labels

In an apparatus comprising a plurality of rack-receiving locations, each configured to receive a rack holding at least one receptacle, and a label reading device configured to read a rack-identifying machine-readable label disposed on the rack and machine-readable labels disposed on the at least one receptacle held on the rack, wherein the label reading device is disposed adjacent to one of the rack-receiving locations, a method for reading machine-readable labels disposed on receptacles carried on a receptacle rack and associating receptacle data read from each machine-readable label disposed on the at least one receptacle with one of the rack-receiving locations, said method comprising:

• (a) placing a rack holding at least one receptacle having a machine readable label disposed thereon in the rack-receiving location disposed adjacent to the label reading device;
• (b) during or after performing step (a), reading the machine-readable label of each receptacle having a machine-readable label to obtain receptacle data for each receptacle having a machine-readable label;
• (c) during or after performing step (a), reading the rack-identifying machine readable label to obtain rack identifying data;
• (d) storing the receptacle data obtained in step (b) and the rack identifying data obtained in step (c) and associating the receptacle data obtained in step (b) with the rack identifying data obtained in step (c);
• (e) removing the rack from the rack-receiving location disposed adjacent to the label-reading device;
• (f) placing the rack removed in step (e) in one of the other rack-receiving locations;
• (g) during or after performing step (f), reading the rack-identifying machine readable label to obtain rack identifying data;
• (h) acquiring location data identifying the rack-receiving location in which the rack was placed in step (f);
• and
• (i) retrieving the receptacle data stored in step (d) that is associated with the rack-identifying data obtained in step (g) and associating the retrieved receptacle data with the location data acquired in step (h) to thereby associate the retrieved receptacle data with the rack-receiving location in which the rack was placed in step (f).