Microplate/microtiter plate

Although other assay containers can be used (e.g., coated tubes or beads), the most popular one is the 96-well microtiter plate. ELISAs that are detected in a microplate luminometer must be performed in opaque white or black plates. 

There are many ways to estimate microbial growth. The simplest is visual inspection of colonies growing on agar plates, though this method is difficult to adapt for HTS. There is a well-known correlation between cell density and optical density, which can be exploited in a 96-well microtiter plate format (e.g., [43]). Measurement of the incorporation of radioactive nutrients is an excellent quantitative method, but has fallen from favor due to concerns about spills and contamination. Finally, both spectrophotometric and fluorimetric assays are conveniently adapted to HTS formats, and Alamar blue is only one example of the tools available for this purpose. As mentioned, we have even found it convenient to use simple visual inspection of Alamar blue plates to identify wells of interest. However, quantification obtainable with a microplate reader is attractive in many settings. 

Quantitation of the amount of enzyme on the microtiter plate by monitoring the enzyme-substrate reaction with a microplate autoreader. 

Microplate Also called microtiter plate, is a flat plastic plate containing rows of multiple that can be used as small test tubes. 

Gentrifuge rotors are available for a large variety of vessels and can in most cases also be made according to the customers specifications. Special swing-out rotors permit evaporation directly from (deep-well) microtiter plates or from vials held in racks with a microtiter plate footprint. Vacuum centrifuges are offered in various sizes, up to machines that can handle 12 or more deep-well microplates (Table 7). 

Initial rate kinetic assays were conducted at 37 C in 50 mM citrate buffer at pH 4.8 in 96-well microtiter plates using /)-nitrophenol P-D-xylopyranoside. For all assays, the XlnD was loaded at 1.5 p.g/ml of reaction, and initial substrate concentrations were varied from 0.1 to 3.2 mM. The release of pNP was monitored every 15 s for the initial 10 min of each reaction by measming the absorbance at 405 nm on a SpectraMax 190 UV/VIS microplate scanner from the Molecular Devices (Sunnyvale, CA). End product inhibition by D-xylose was confirmed by ranning identical assays to those described above with initial D-xylose concentrations ranging from 3.33 to 40 mM. Triplicate analyses of all assays were run at all conditions. All parameters estimated in this study were calculated using standard Michaelis-Menten kinetics as described previously [11]. 

Figure 9 Carbohydrate microplate arrays prepared by the noncovalent immobihzation of aliphatic alkyne-derivatized carbohydrates to microtiter plate surfaces. Carbohydrates can then be screened against a variety of biologically important substrates such as lectins and RNA.

Figure 10 Carbohydrate microplate arrays prepared by the noncovalent immobilization of azide-derivatized carbohydrates to microtiter plates via a 1,3-dipolar cycloaddition reaction between alkynes and azides. Carbohydrates displaying terminal azides can be captnred on microtiter plate surfaces through a terminal alkyne attached to a long, ahphatic tether and screened directly on the microtiter plate surface.

In its details, this works as follows. The sample (tissue or protein solution) is hydrolyzed to the amino acids over 24 h in microfuge tubes with 0.5 ml 6-NHCl at 100° C. Starcher dries the hydrosylate on the speed-vac and dissolves it again in water. An aliquot is then pipetted onto a microtiter plate and ninhydrine reagent is added. Starcher lets the plate float for 10 minutes in a boiling water bath, whereupon the assay is done and can be read in the microplate reader. 

Microtiter plates (MaxiSorp-immunoplates, NUNC A/S, Roskilde, Denmark) were coated overnight at 23°C with the cohesin test samples (200 pl/well, 270 nM of miniCipC c, wild-type or mutated Coh2CBD t). The plates were blocked for 2.5 h with blocking solution (300 pl/well 3% (w/v) bovine serum albumin in TrisNC buffer) and washed three times with TrisNC buffer (300 pl/well). The cohesin-dockerin interaction was initiated upon addition of dockerin samples (200 pl/well, 94 nM of XynDocA c or XynDocS t), and the plates were incubated for 2.5 h. After five washes, the bound dockerins were detected by means of the fused-xylanase activity substrate solution (240 pl/well 2.9 mM / -nitrophenyl p-D-cellobioside) was added followed by incubation at 60 C. Optical density was detOTnined at 420 nm on a VERSAmax microplate reader (Molecular Devices Corp., Sunnyvale CA). 

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