In order to be able to """"""""photoablate"""""""" a chosen organelle or structure with nanosecond pulses of green (532 nm) laser light, the energy output of the laser must closely approximate a Gaussian distribution across the beam profile. It has been our experience that maintaining such a profile requires that the laser be constantly tuned and aligned (both within the laser head and also along the optical train) throughout the workday. To facilitate these operations we added a laser beam analyzer (LBA 300PC, Spiricon Inc) to our optical trapping/laser microsurgery workstation that graphically displays the beam profile in real time. Using this analyzer we confirmed that the laser profile changes on a day-to-day basis, and that the ability to photoablate cell structures is sensitive to these changes. In order to improve the long-term stability of the beam, and to generate reproducible experimental results, we inserted pinhole apertures of various sizes into different places within the laser cavity. This well known """"""""trick"""""""" allows us to now use only the most stable (central portion) of the laser beam during our ablation studies. The """"""""best"""""""" size and placement of the aperture was determined from viewing the beam on the laser analyzer to check for maxima, and also experimentally by using it to ablate different cellular structures. We found that a 1.4 mm aperture placed between the rod and the front mirror yielded the best performance. Before the pinhole was added the fit to Gaussian was approx. 0.7 were as once the aperture was in place it was 0.85. Because this modification significantly decreased the beam diameter, we added a beam expander/collimator to increase the diameter to that of the back aperture of the objective lens.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
Biotechnology Resource Grants (P41)
Project #
Application #
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Wadsworth Center
United States
Zip Code
Booth, David M; Enyedi, Balázs; Geiszt, Miklós et al. (2016) Redox Nanodomains Are Induced by and Control Calcium Signaling at the ER-Mitochondrial Interface. Mol Cell 63:240-248
Mannella, Carmen A; Lederer, W Jonathan; Jafri, M Saleet (2013) The connection between inner membrane topology and mitochondrial function. J Mol Cell Cardiol 62:51-7
Takvorian, Peter M; Buttle, Karolyn F; Mankus, David et al. (2013) The multilayered interlaced network (MIN) in the sporoplasm of the microsporidium Anncaliia algerae is derived from Golgi. J Eukaryot Microbiol 60:166-78
Forbes, Stephen J; Martinelli, Daniel; Hsieh, Chyongere et al. (2012) Association of a protective monoclonal IgA with the O antigen of Salmonella enterica serovar Typhimurium impacts type 3 secretion and outer membrane integrity. Infect Immun 80:2454-63
Wang, Ruiwu; Zhong, Xiaowei; Meng, Xing et al. (2011) Localization of the dantrolene-binding sequence near the FK506-binding protein-binding site in the three-dimensional structure of the ryanodine receptor. J Biol Chem 286:12202-12
Marko, Michael; Leith, Ardean; Hsieh, Chyongere et al. (2011) Retrofit implementation of Zernike phase plate imaging for cryo-TEM. J Struct Biol 174:400-12
Lu, Zonghuan; McMahon, Jay; Mohamed, Hisham et al. (2010) Passive Microfluidic device for Sub Millisecond Mixing. Sens Actuators B Chem 144:301-309
Bernhard, Joan M; Goldstein, Susan T; Bowser, Samuel S (2010) An ectobiont-bearing foraminiferan, Bolivina pacifica, that inhabits microxic pore waters: cell-biological and paleoceanographic insights. Environ Microbiol 12:2107-19
Liu, Zheng; Wang, Ruiwu; Tian, Xixi et al. (2010) Dynamic, inter-subunit interactions between the N-terminal and central mutation regions of cardiac ryanodine receptor. J Cell Sci 123:1775-84
Springer, Deborah J; Ren, Ping; Raina, Ramesh et al. (2010) Extracellular fibrils of pathogenic yeast Cryptococcus gattii are important for ecological niche, murine virulence and human neutrophil interactions. PLoS One 5:e10978

Showing the most recent 10 out of 252 publications