One-Cuvette Sample Compartment •••The one position sample compartment is standard on this ISS Product. The turret holds one 10 mm x 10 mm cuvette, however, adapters can be provided for alternative sized cuvettes. The compartment is inclusive of computer controlled stirrers whose speed can be controlled by the potentiometer dial on the front plate. The front plate also houses connector ports for a temperature bath and nitrogen intake.
Two-Cuvette Sample Compartment ••••The fully automated, computer-controlled two cuvette sample compartment with the liquid cooling option is also offered for this ISS product. The turret holds two 10 mm x 10 mm cuvettes. Adapters can be provided for differently sized cuvettes. Like the one position sample compartment, the two-cuvette sample compartment includes computer-controlled stirrers, and their speed is controlled by the potentiometer dial on the front plate. The front plate also contains connector ports for a temperature bath and nitrogen gas intake.
Three-Cuvette Sample Compartment ••••Unique to ISS is the three-position, computer-controlled sample compartment with a flow through system for temperature control. The compartment's primary use is for automated time-resolved measurements in the presence of background fluorescence: the first compartment contains the sample cuvette, the second compartment contains the reference cuvette and the third compartment is reserved for the cuvette that is used to estimate the fluorescence background.
Four-Cuvette Sample Compartment ••••The four-cuvette, Peltier-controlled, sample compartment provides temperature and magnetic stirring to all four cuvettes simultaneously (same temperature and same speed rate) and has a dry gas purge system. The temperature range is from -25°C to +105°C (0.02°C). It holds a standard 10 mm x 10 mm cuvette, and the optical center is 8.5 mm above the bottom of the cuvette, which also allows the use of microcuvettes.
Absorption Measurements Accessory ••••The ISS absorption accessory allows the user to determine the wavelength dependent optical density of a sample. Like other spectrophotometers on the market, it follows the Lambert-Beer law for non-scattering, non-aggregated, optically homogeneous samples. Highly scattering aggregates or fluorescent samples require additional corrections.
Dewar Flask ••••For cryogenic studies, ISS offers a Dewar sample compartment for both steady-state and lifetime instrumentation. The insulating Dewar is filled with liquid nitrogen and comes with:
- Three(3) quartz windows with a transmission range of 180-2600 nm.
- A low temperature cuvette holder.
- A cuvette extraction/insertion rod.
- Baseplate for mounting the Dewar to the instrument.
One fill of liquid nitrogen will last up to 4-5 hours.
Total Internal Reflection Fluorescence (TIRF) Flow Cell ••••TIRF spectroscopy is a very powerful and versatile technique for studying surface and interfacial behavior of biological molecules and their aggregates. The ISS TIRF flow cell provides in situ, real-time, nondestructive, and highly sensitive detection for studies on low quantities of expensive biological materials (~10 nL, minimum).
Variable-angle, Front Surface Sample Compartment ••••In the study of membranes or solid samples, the major problem is holding the sample at an angle with respect to the excitation and emission channels to optimize both the incident and the fluorescent intensities. Choosing less than the optimum angle increases the amount of scattered light in the detector, which sometimes overwhelms the fluorescent signal. Alternatively, when scattering is to be detected than fluorescence may be a significant interference at a non-optimal angle.
The Variable-Angle accessory is designed to help in such cases. An up to 2 mm thick (in pathlength) cuvette holder can be installed. A film or a solid sample can be sandwiched between two glass slides of appropriate dimensions and be inserted in the cuvette holder. By rotating the handle, the sample can be positioned at the desired angle.