Optical monitoring of protein crystals in time-resolved x-ray experiments: Microspectrophotometer design and performance
Abstract
We describe a single crystal microspectrophotometer for optical monitoring of protein crystals during time-resolved x-ray diffraction experiments. It is a single beam device with a diode array detector for simultaneous multiwavelength measurement of optical spectra. The time resolution of the microspectrophotometer is 2.5 ms, which matches the ms time resolution of the x-ray experiments obtained at existing synchrotron sources. Optical densities of single crystals can be reliably measured up to 2.5 OD, with the linear range extending to 2 OD. The tight focusing of the light beam allows monitoring of crystals as small as 30-50 μm, an important feature since successful reaction initiation and optical monitoring of crystals in time-resolved x-ray diffraction experiments often require very small crystals. The compact design of the microspectrophotometer and the long objective-to-crystal distance make it compatible with the crowded environment of time-resolved x-ray diffraction experiments.
- Publication:
-
Review of Scientific Instruments
- Pub Date:
- May 1994
- DOI:
- 10.1063/1.1144883
- Bibcode:
- 1994RScI...65.1506C
- Keywords:
-
- Arrays;
- Crystals;
- Diodes;
- Proteins;
- Spectrophotometers;
- Synchrotrons;
- X Ray Analysis;
- X Rays;
- Xenon Lamps;
- Density Measurement;
- Electromagnetic Absorption;
- Focusing;
- Light (Visible Radiation);
- Optical Density;
- Signal To Noise Ratios;
- Optics