Optical Temperature Verification More and more laboratories now require regular verification testing of instrument performance as part of their standard operating procedures. This is especially true for laboratories with validated protocols that must remain repeatable and transferable. However, instrument verification normally requires a technical service visit and specialized testing equipment—a process that can be both intrusive and expensive. The OTV Solution We have recently developed a simple and automated solution for performance verification and dynamic calibration of the Rotor-Gene. Our OTV (optical temperature verification) system* uses a pre-calibrated consumable whose optical properties change at precise thermal checkpoints to test performance (Fig 1). A software Wizard makes the test procedure a simple click-and-run operation. A printable post-run report (Fig 2) documents each test and, in the unlikely event the Rotor-Gene requires re-calibration for thermal accuracy, this is also automatically adjusted and reported. Each test takes only minutes and can be repeated at any time. How OTV Works The OTV system uses the chemical properties of thermochromic liquid crystals (TLCs) as an absolute temperature reference. When heated, a TLC changes from opaque to transparent at a very precise temperature. The Rotor-Gene can measure this precise temperature transition point and, by comparing the measured in-tube thermal transition point to the known calibrated value, the software can verify that the Rotor-Gene is within specification. If not, automatic re-calibration of the Rotor-Gene can be done at the press of a button. We formulate three types of TLCs, each with a different thermal transition temperature. This allows us to check reference temperatures of 50°C, 75°C, and 90°C. However, every batch of TLC crystals has a slightly different specific melting temperature. To allow for this, the absolute melting temperature of the particular TLC batches used are encoded in the OTV Disc serial number. So to ensure accuracy, it’s important to specify the correct serial number in the software Wizard. OTV Kit The OTV kit (P/N 3001-026) comprises a calibrated and pre-configured OTV Disc, optical insert accessories, and a CD. (Note: a standard RotorDisc 72 rotor is required but not supplied with the kit). With the kit, verification of instrument performance and thermal accuracy can be repeated up to 30 times within the 6 month expiry date of the OTV Disc consumable. Automated verification testing is unique to the Rotor-Gene and it makes the verification test process incredibly simple! * patent pending

Fig 1: Close-up of OTV Disc in a RotorDisc 72 rotor. The thermochromic crystals (TLCs) are arranged in replicates of four around the disc, each having a slightly different opalescent color.       Fig 2: Example OTV report. The HTML report file can be saved, printed, e-mailed or exported to MS Word as a record of the verification test. Detailed analysis data is also reported.                            Fig 3: OTV kit. Comprises OTV Disc, optical insert accessories, and CD.