Multipinned phase

An operating mode of a CCD called multipinned phase (MPP) allows a hundredfold dark current reduction at room temperature [21],... 

Liquid chromatography-electrogenerated chemiluminescence Lithium diisopropylamide Low-density lipoprotein Laser-induced fluorescence Limit of detection Monoclonal antibody Maximum admissible concentration l,2-B (3-chlorophenyl)ethylenediamine Micellar electrokinetic chromatography 4,4 - Oxalyl 6 [(trifluoromethylsulfonyl)imino]-ethylene 6 (4-methylmorpholinium)trifluoromethanesulfonate Maltose phosphorylase Multipinned phase... 

Multipinned phase (MPP) is an electronic technique that significantly reduces the dark current, with some cost in the full well capacity. MPP devices exhibit dark currents that are 1 to 2 orders of magnitude lower than similar non-MPP CCDs at the same temperature. Conversely, an MPP CCD may be operated at higher temperature and exhibit as low a dark current as a much cooler non-MPP device. This feature is attractive when the user wants to avoid liquid nitrogen cooling. MPP CCDs cooled by an air-cooled thermoelectric cooler can easily exhibit dark currents in the region of 1 e /pixel/sec. 

Ede NJ, Bray AM. A simple linker for the attachment of aldehydes to the solid phase. Application to solid phase synthesis by the Multipin method. Tetrahedron Lett 1997 38 7119-7122. 

Using the Multipin method, Gilbertson then synthesized 27 undecapeptides on solid phase, which were presumed to have a helical conformation. This was induced by frequent use of the a-alkylated amino acid aminoisobutyric acid. The phosphine-thiooxide-containing residues were positioned in the i and i + 4 positions, which would lead to the two phosphines being adjacent in the helical peptide chain. In addition, Gilbertson synthesized 36 peptides containing phosphines in the i and i + 1 positions. 

Another system proposed for use in solid-phase systems is called the multipin system, originally developed by H. Mario Geysen, then at Australia s Commonwealth Serum Laboratories. Geysen s system makes use of one of the most popular tools of immunological research, the 96-well polyethylene plate consisting of eight rows of 12... 

Bray, A. M. Chiefari, D. S. Valerio, R. M. Maeji, N. J. Rapid Optimization of Organic Reactions on Solid Phase Using the Multipin Approach Synthesis of 4-Aminoproline Analogs by Reductive Animation, Tetrahedron Lett. 1995,36, 5081. 

Ede, N. J. Bray, A. M. A Simple Linker for the Attachment of Aldehydes to the Solid Phase. Application to Solid Phase Synthesis by the Multipin Method, Tetrahedron Lett. 1997, 38, 7119. 

Recent literature contains a multitude of examples of synthetic organic methodologies which have been optimized and applied to the solid-phase synthesis of combinatorial libraries [2]. In fact, the production of a number of these libraries has been realized on such systems as the Multipin SPOC [8], the DIVERSOMER [9] and the OntoBLOCK [10], All three apparatuses allow the automated production of spatially dispersed combinatorial libraries and facilitate the isolation, identification, screening and archiving of single compounds in distinct physical locations which are crucial factors during lead discovery and optimization. 

Using the Multipin SPOC systems, researchers at Chiron have demonstrated the automated solid-phase synthesis of peptoids 1 (Scheme 1) [12], while Ellman and co-workers have completed the synthesis of a combinatorial library of 11 200 spatially dispersed benzodiazepines 2 (Scheme 2) [13],... 

Bray AM, Jhingran AG, Valerio RM, Maeji NJ, Simultaneous multiple synthesis of peptide amides by multipin method. Application of vapor-phase ammonolysis, J. Org. Chem., 59 2197-2203, 1994. 

A useful vapor-phase ammonolysis has been developed for simultaneous multiple synthesis of peptide amides by both the resin and multipin methods. Pins or peptide-resins are deprotected and washed with CHjCb, DMF, and CH2CI2, and are then air-dried. A bottle of NH3/THF (3 7 v/v, 50-100 mL) was cooled to —78 °C and placed in a well-greased desiccator together with the multipin pin holders (1-4) or the open vials containing resins (130mg/vial). The desiccator was clamped shut, partially evacuated (10 s), and then left to stand at 20°C for 24 h. After this time, the multipin pin holders and the resins were removed from the dessicator and allowed to stand for 30 min. Qeaved peptides were eluted from the pins by immersing them in MeCN/H20 (4 6) for 3 h, or from the resins by washing with AcOH/MeCN/HjO (3 4 3, 5 x ImL). 

Takahashi, T Ebata, S. Doi, T. Solid Phase Approach to Muscone Synthesis Rh(I)-Catalysed Hydroformylation of a 1,1-Disubstituted Alkene on the Multipin Sysitm, Tetrahedron Lett. 1998,59, 1369. 

J. L. Aubaganac, C. Enjalbal, et al.. Application of time-of-flight secondary ion mass spectrometry to in situ monitoring of solid-phase peptide synthesis on the multipin system, J. Mass Spectrom. 33, 1094-1103 (1998). 

Bray, A.M. et al., Rapid optimization of organic reactions on solid-phase using the Multipin approach synthesis of 4-aminoproline analogs by reductive amination. Tetrahedron Lett., 36, 5081, 1995. 

More recently, several papers reporting the solid phase synthesis of peptide aldehydes have been published. Dinh and Amstrong (61) outline the use of Weinreb-type amides on solid support for the synthesis of ketones and aldehydes Ede and Bray (62) report a new linker based on the oxazolidine moiety and use this method with Multipin technology Galeotti et oL (63) apply their thiazolidinyl linker to a solid support. The great interest in these aldehydic compounds has also been demonstrated by the fact that the Weinreb amide resin is now commercially available from Bachem and Novabiochem. 

---