Picoliter volume

Several methods have been used for the matrix application (1) immersing a tissue section quickly in a matrix solution, (2) spraying matrix solution onto a tissue section with an air brush, (3) putting small droplets of matrix solution onto a tissue section with an automatic pipetting device that can dispense picoliter volumes (lpL = 10 pk) of reagents.4,5,715161819... 

The Chemical Inkjet Printer (ChIP), an inkjet printer-like device which is equipped with a piezoelectric reagent-dispensing system, has been developed by Shimadzu Corporation. The ChIP can dispense picoliter volumes of matrix solution onto a tissue section, which has four printing heads and nozzles that have no contact with the tissue section surface. 

Yin, D. Barber, J. P. Hawkins, A. R. Schmidt, H., Highly efficient fluo rescence detection in picoliter volume liquid core waveguides, Appl. Phys. Lett. 2005, 87, 211111... 

In the diffusive interfacial transport-refractive index (DIT-NDX) method, compositions are determined using precise refractive index data (8). Refractive index data valid to +/- 0.00005 are obtainable using the DIT apparatus vithin an area of 30 ym2 in a sample approximately 25-ym thick (0.75 picoliter volume). Data collection and analysis require 9 seconds. The accuracy, spatial resolution, and speed vith vhich refractive indices can be determined are thus superb. 

He, B., Burke, J., Zhang, X., Zhang, R., Regnier, F. E., A picoliter-volume mixer for microfluidic analytical systems, Anal. Chem. 2001, 73, 1942-1947. 

Separation of simple mixtures [13,44] to more complicated biofluidic mixtures with CE-NMR and CEC-NMR have been reported [51,52], Several instrumental modifications and methodologies have been described to use CE/CEC-NMR as a diagnostic tool [44,53-55], Though still in its infancy, chip-based CE-NMR with microfabricated microcoils may be able to analyze picoliter volume samples [56,57]. 

Microfluidics is a key functionality in the success of microdevices. It is defined as a branch of physics and biotechnology that studies the behavior of fluids at tire microscale and mesoscale, volumes thousands of times smaller than a common droplet. It also concerns the design of systems in which such small volumes of fluids will be used. For example, the gene chips and labs-on-a-chip are based on the transport of nanoliter or picoliter volumes of fluids through microchannels within a glass or plastic chip. 

FIGURE 11.1 (See color insert following page 210.) General overview of MALDI-IMS. (a) Fresh section cut from sample tissue, (b) Mounted section after matrix application using a robotic picoliter volume spotter, (c) Partial series of mass spectra collected along one row of coordinates U-axis). (d) Three-dimensional volumetric plot of complete dataset with selected m/z slices or ion images. Principal axes are x, y, and m/z. Color of each voxel is determined by ion intensity. (From Cornett, D. et al., Nat. Methods, 4, 828, 2007. With permission.)... 

Other less-common deposition methods include electrospraying in a stable cone-jet mode to generate highly reproducible spots of as little as 50-pL volumes [33] and a laser transfer technique that allows the accurate deposition of picoliter volumes of proteins onto the solid surface [34]. 

Larson, A. R, Ahlberg, H., and Folestad, S., Semiconductor laser-induced fluorescence detection in picoliter volume flow cells, Appl. Opt., 32, 794,1993. 

Microfluidics Lab-on-a-chip technology based on the transport of nanoliter or picoliter volumes of fluids through microchannels within a glass or plastic chip. Microfluidics systems evolved from MEMS research. 

Robust giant lipid vesicles and micro-electroporation technology for controllable manipulation of picoliter volumes on-chip. Bioelectrochemistry 69. 

The immobilized spots used in protein microarrays may contain protein molecules or smaller molecules such as inhibitors or ligands with which a protein in solution may interact. Very small spots are advantageous in that higher detection throughput can be achieved with minimal amounts of printed material and sample. Spots are typically deposited either by contact methods, such as printing arrayers that use needles to deposit droplets directly on the surface, or by non-contact methods, including the use of capillaries or ink jet dispensers to deposit droplets with nanoliter-picoliter volumes. 

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