TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Apparatus: (I) includes temperature sensors spaced along the length of each channel for measuring the temperature profile, a detector (24) measuring an optical characteristic of the molecules as they pass along the channels. The optical characteristic is fluorescence, and the detector, preferably, hybrid photodiode or multi-anode photo-multiplier tube detects the molecular fluorescing in response to UV illumination as they pass along the channels. Optionally, the optical characteristic is UV absorption, and the detector, preferably, a charge-coupled device or a photodiode array, detects a reduction in transmitted UV illumination, as a result of molecular absorption. (I) includes first and second detectors for simultaneously measuring respective first and second optical characteristics of the molecule as they pass along the channels. The first detector detects the molecules fluorescing in response to UV illumination, and the second detector detects a reduction in transmitted UV illumination as a result of molecular absorption. (I) includes a UV source (22) for creating the UV illumination. The chip is oriented so that the molecules pass along the channels under the influence of gravity. Optionally, the molecules are pumped along the channels or are urged along by an electric force. (I) includes computer analysis unit (26), receiving an output for each detector and arranged to analyze the output (30) or outputs as a function of molecular temperature, and an apparatus control (32) arranged automatically to control operation of the apparatus in dependence upon an output of the computer analysis unit. The apparatus control actuates a molecule collection mechanism, for automatically collecting a sample of selected molecules from a channel. The molecule collection mechanism includes voltage switching unit for switching the sample into a side branch of the channel. The computer analysis unit calculates a cross-correlation between an output or outputs indicative of known molecules in a control channel and an output or outputs indicative of molecules for analysis in another channel. The heating elements are controllable to create a user-defined temperature profile along the channels, and are controlled to create a monotonic increasing or decreasing temperature profile along the channels, or to create a multi-valued temperature profile along the channels. (I) includes first and second detectors measuring respective first and second optical characteristics of the molecules. The detectors are receptive to light of first and second wavelengths, respectively.Preferred Method: The optical characteristic is analyzed as a function of position along the channel, each position uniquely defining a temperature at that position in accordance with the profile. The optical characteristic is molecular fluorescence or the molecules' capacity for UV absorption. The method includes simultaneous detection of first and second optical characteristics, where the first optical characteristic is molecular fluorescence and the second is the molecules' capacity for UV absorption. The method includes the step of automatically collecting selected molecules in dependence upon a result of analyzing the detected optical characteristic as a function of temperature. The method preferably involves passing control molecules along a control channel, adjacent to the channel carrying molecules to be analyzed; detecting a corresponding optical characteristic or characteristics of the control molecules; and comparing the optical characteristic or characteristics of the molecules to be analyzed with the corresponding optical characteristic or characteristics, and calculating a cross-correlation between the characteristic or characteristics and the corresponding characteristic or characteristics.