Borgstahl Lab

Topography is the high spatial resolution study of an individual reflection. It reveals the mosaic structure of the crystal. Normally the images are captured with high resolution nuclear emulsion plates. This process is time consuming and complicated. It can take a long time to acquire complete data for a single reflection.

We have replaced the film with a CCD. We use direct conversion of the X-rays at the surface of the CCD to collect the data. The CCD does not have the same high resolution of the nuclear emulsion plates but it is much faster and easier to use with almost comparable resolution.

Initial Results

First topograph recorded at NSLS Feburary 2002.

Frame from first sequence recorded at NSLS (Reflection is approximately 384x512 um) The CCD had 4x4 um square pixels. Click on the frame to download a movie of the entire sequence.

Room Temperature Results

MarCCD coarse image with area of topography collection exploded.

Summation of topographs for each reflection. Reflections are shown approximately 2x normal size.

Cryo Results

Two regions of a cryogenically frozen crystal of lysozyme where digital topographs were taken of size reflections in each region.

Summation of topographs for each reflection. Reflections are shown approximately 2x normal size.

Shown are two different reflections that were sampled every 0.001 degrees for a total of one degree. Below is the corresponding coarse oscillation image with the predicted reflection locations overlaid with red circles. Reflections overlaid in yellow circles failed to pass a series of filters designed to find usable reflection profiles that were accurately recorded. Reflections with black and green crosshairs are further analyzed below.

Coarse Oscillation Image from an Earth-grown Insulin Crystal

Coarse (1.0°) Oscillation Image From an Earth-grown Insulin Crystal

Topography/Reflection Profile/3D Reflection Animations

For each reflection, the following comparisons are made (From left to right): (1) coarse image (1.0°), (2) topographs and corresponding reflection profile from the super fine phi (0.001°) slicing technique, and (3) 3-D reconstruction from the super fine phi images (0.001°) with x and y detector pixel positions and z phi angle in degrees.

Reflection H=-20 K=1 L=10 (Black)

Coarse Image

Topograph/Reflection Profile (0.001° sampling)

3D Reflection Rotation

(rotation about vertical phi axis)

Reflection H=16 K=7 L=-3 (Green)

Coarse Image

Topograph/Reflection Profile (0.001° sampling)

3D Reflection Rotation

(rotation about vertical phi axis)

Coarse Oscillation Image from a Microgravity-grown Insulin Crystal

Coarse (1.0°) Oscillation Image From a Microgravity-grown Insulin Crystal

Topography/Reflection Profile/3D Reflection Animations

Reflection H=1 K=6 L=12 (Black)

Coarse Image

Topograph/Reflection Profile (0.001° sampling)

3D Reflection Rotation

(rotation about vertical phi axis)

Reflection H=-18 K=32 L=-2 (Green)

Coarse Image

Topograph/Reflection Profile (0.001° sampling)

3D Reflection Rotation

(rotation about vertical phi axis)

Shown are three different reflections that were sampled every 0.01 degrees for a total of five degrees. Below is the corresponding coarse oscillation image with the predicted reflection locations overlaid with red circles. Reflections overlaid in yellow circles failed to pass a series of filters designed to find usable reflection profiles that were accurately recorded. Reflections with black and green crosshairs are further analyzed below.

Coarse Oscillation Image from an Actin:Profilin Crystal

Coarse (5.0°) Oscillation Image From a Microgravity-grown Insulin Crystal

Topography/Reflection Profile/3D Reflection Animations

For each reflection, the following comparisons are made (From left to right): (1) coarse image (5.0°), (2) topographs and corresponding reflection profile from the super fine phi (0.01°) slicing technique, and (3) 3-D reconstruction from the super fine phi images (0.01°) with x and y detector pixel positions and z phi angle in degrees.