J 2014

Gas-assisted annular microsprayer for sample preparation for time-resolved cryo-electron microscopy

LU, Z.H., D. BARNARD, Tanvir SHAIKH, X. MENG, C.A. MANNELLA et. al.

Basic information

Original name

Gas-assisted annular microsprayer for sample preparation for time-resolved cryo-electron microscopy

Authors

LU, Z.H. (840 United States of America), D. BARNARD (840 United States of America), Tanvir SHAIKH (840 United States of America, guarantor, belonging to the institution), X. MENG (840 United States of America), C.A. MANNELLA (840 United States of America), A.S. YASSIN (840 United States of America), R.K. AGRAWAL (840 United States of America), T. WAGENKNECHT (840 United States of America) and T.M. LU (840 United States of America)

Edition

JOURNAL OF MICROMECHANICS AND MICROENGINEERING, BRISTOL, IOP PUBLISHING LTD, 2014, 0960-1317

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10600 1.6 Biological sciences

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 1.731

RIV identification code

RIV/00216224:14740/14:00079215

Organization unit

Central European Institute of Technology

UT WoS

000345262800001

Keywords in English

microfluidics; micronozzle; microspray; microdroplet; monolithic device; cryo-EM; time-resolved TEM

Tags

International impact, Reviewed
Změněno: 25/2/2015 09:20, Martina Prášilová

Abstract

V originále

Time-resolved cryo-electron microscopy (TRCEM) has emerged as a powerful technique for transient structural characterization of isolated biomacromolecular complexes in their native state within the time scale of seconds to milliseconds. For TRCEM sample preparation, a microfluidic device has been demonstrated to be a promising approach to facilitate TRCEM biological sample preparation. It is capable of achieving rapidly aqueous sample mixing, controlled reaction incubation, and sample deposition on electron microscopy (EM) grids for rapid freezing. One of the critical challenges is to transfer samples to cryo-EM grids from the microfluidic device. By using a microspraying method, the generated droplet size needs to be controlled to facilitate thin ice film formation on the grid surface for efficient data collection, whilst not being so thin that it dries out before freezing, i.e. an optimized mean droplet size needs to be achieved. In this work, we developed a novel monolithic three dimensional (3D) annular gas-assisted microfluidic sprayer using 3D MEMS (MicroElectroMechanical System) fabrication techniques. The microsprayer demonstrated dense and consistent microsprays with average droplet size between 6 and 9 mu m, which fulfilled the droplet size requirement for TRCEM sample preparation. With droplet density of around 12-18 per grid window (window size 58 x 58 mu m), and a data collectible thin ice region of >50% total wetted area, we collected similar to 800-1000 high quality CCD micrographs in a 6-8 h period of continuous effort. This level of output is comparable to what were routinely achieving using cryo-grids prepared by conventional blotting and manual data collection. In this case, weeks of data collection with the previous device has been shortened to a day or two. And hundreds of microliters of valuable sample consumption can be reduced to only a small fraction.