Plates 384-microtubes

Storage and retrieval of 384-micro tube plates In system plate-to-plate microtube trausfer... 

The microfluidic chip system for preparing a miniaturized PMBV/PVA hydrogel consists of a two-chamber chip, an aluminum custom-made chip holder, Teflon capillaries, microtubes, and syringes equipped with a microsyringe pump (Fig. 15). The two-chamber chip was fabricated by a photolithographic wet etching technique. Whereas both channels and chambers (200 pm in depth) were fabricated on the top plate, only chambers (200 pm in depth) were fabricated on the bottom plate. 

The assembly of large screening libraries for HTS requires the development of archival and retrieval systems that can handle solid compounds and compound solutions in microtubes or in plates in either the 96 or the 384 format. Barcodes are used to identify each sample vial, tube, or plate. Databases record which samples are available, what type of sample it is, and how much is available. All solid samples are prepared first as stock (master) solutions ( around 5 mg/mL in DMSO) in 2-D bar-coded tubes that are then aliquotted to plates and processed as described earlier. The tubes and plates are usually made of polypropylene for compatibility with DMSO. DMSO is the industry standard solvent for screening libraries because many of the archived compounds are not soluble in water at 5 mg/mL. DMSO, an organic solvent, also has a favorable combination of biological... 

Fit a 96-well microtiter plate (200 pL) or 2-mL collection microtubes into the vacuum manifold, carefully aligning the drop-formers to the receiver plate wells. Add 100 pL elution buffer and incubate for 2 min. Then apply a vacuum of 200-400 mbar and release vacuum after material has flowed through. Store the plate of eluted proteins at 4°C for short term or until evaluated, and then at -80°C for longterm storage. 

For a simple example, suppose a customer from HTS orders 3000 samples of 40 nL of 5 mM solution each in 384-well assay-ready plates for confirmation after a primary screen. The workflow to fill this order can involve retrieval from main stock of 10 mM in microtubes from the storage system, creation of intermediate plates by diluting the samples to 5 mM with 4 pL stock and 4 pL DMSO, then producing final assay-ready plates by using a replication system capable of making 40-nL transfers. Up to three systems may be involved, depending on the set-up, so more than one workflow may be required to fill some orders. 

Microtube Plate for High-Throughput Retrieval of Compound Subsets... 

Figure 2 The 384-microtube plate developed for high-throughput retrieval of compound subsets from large compound collections. At Roche, the 384-microtube plate is used for high-throughput cherry picking of compound samples from the HTS library for hit validation and secondary screening...

The Liquid Master Store at Roche uses a 96-tube version of the microtube plate described in Section 1.4 a description of the 96-tube plate is found on the web site www.remp.com. The individually accessible tubes in 96-tube plates in the Liquid Master Store hold a few definite sample volumes, e.g. 26 J,L and 140 J,L per tube. Storage and retrieval of HTS master solutions with fixed sample volumes facilitate the sample logistics considerably. Upon retrieval from the Liquid Master Store, the master solutions in the 96-tube plates are thawed and transferred to 384-well plates before they enter the downstream aliquoting process. This sample-handling concept avoids repetitive freeze-thaw cycles of HTS master solutions and thereby improves the stability and integrity of the compound samples used in HTS. 

The master solutions in the liquid master store are also used to produce multiple copies of single-use aliquots in 384-microtube plates, which are used for two processes (i) loading of the Smart Compound Depository with new compound aliquots, and (ii) replenishment of frequently ordered compounds in this depository. The continuous replenishment of frequently ordered compounds through the Liquid Master Store... 

The plate-to-plate tube transfer at -20 °C in the Liquid Master Store and in the Smart Compound Depository are similar robotic operations that can be combined in one automated sample bank. The combination of 96-tube and 384-microtube plate-to-plate tube transfer in one system might be the preferred solution for sample management of small- and medium-sized HTS libraries. 

Detach the cells from some wells of the 24-well plate to verify overexpression of the protein under study. To this end, add 400 [il PBS containing 8 mM EDTA, pH 7.4 (PBS-EDTA), to the well, and leave at 37°C for 5 to 10 min. Detach the cells by rinsing the well several times with the PBS-EDTA. Transfer the cells in PBS-EDTA to a microtube, and centrifuge for 10 min at 2000 g. Resuspend the cells in 500 il electrophoresis sample buffer without SDS, sonicate, add 60 jil of 20 % SDS and boil the sample for 2 min before electrophoresis. 

Use a collection plate or microtube rack as the source container, pellet the precipitated protein at the bottom of the wells by centrifugation, and aspirate the supernatant for analysis. 

Station offers direct HPLC injections, or loading 4-mL WISP vials, GC vials or deep-well microtiter plates or microtubes. 

Figure 16.26 MS detectors, (a) Discrete dynode model with active film (reproduced courtesy of ETP Scientific Inc.) (b) Continuous dynode model. Diagram of a channeltron the funnel shaped cathode permits the recovery of ions issuing from different trajectories. The curvature has the effect of preventing the positive ions which appear by the impact of electrons on the residual molecules and restricting therefore the production of further electrons (c) MicroChannel plate. Each plate consists of an array of tiny glass tubes. Each channel becomes a continuous dynode electron multiplier (d) Details of the conversion cathode. Multiplication of the electrons in a microtube (from illustration by Galileo USA).

C. Fukuhara, Y. Kamata, A. Igarashi, Catalytic performance of microtube-type copper-based catalyst for methanol steam reforming, prepared on the inner wall of an aluminum tube by electroless plating, Appl. Catal. A-Gen. 296 (2005) 100. 

In this work, heat and fluid flow in some common micro geometries is analyzed analytically. At first, forced convection is examined for three different geometries microtube, microchannel between two parallel plates and microannulus between two concentric cylinders. Constant wall heat flux boundary condition is assumed. Then mixed convection in a vertical parallel-plate microchannel with symmetric wall heat fluxes is investigated. Steady and laminar internal flow of a Newtonian is analyzed. Steady, laminar flow having constant properties (i.e. the thermal conductivity and the thermal diffusivity of the fluid are considered to be independent of temperature) is considered. The axial heat conduction in the fluid and in the wall is assumed to be negligible. In this study, the usual continuum approach is coupled with the two main characteristics of the microscale phenomena, the velocity slip and the temperature jump. 

The equations to be solved are similar to those in the previous section with some minor differences due the change in geometry (parallel-plate microchannel versus microtube). In the solution, slip boundary conditions given in Eqs. (I) and (2) are applied and finite element method is used to solve for the velocity profile and the temperature distribution. Then, from the temperature profile, the local Nu is determined. 

Collect HPLC fractions based on time (e.g., 1-2 minutes per fraction) by use of an automated sample collector, kept at 4°C, with 1.5-mL Agilent Well Plate fraction collector (325-pL fractions are typically collected per 1.5-mL microtubes). 

Aliquot 10 xL of genomic DNA from the cell extracts into microtubes or 96-well plates (U-shaped)... 

Using a repeater pipet, aliquot 10 [xL of the 2X restriction mix to the DNA samples Centrifuge briefly (microtubes) or tap (96-well plates) to bring the mix to the bottom of the wells. Incubate overnight at 37°C (use a humidified atmosphere if digesting in 96-welI plates). 

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