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Biotech / Medical : Ciphergen Biosystems(CIPH): -- Ignore unavailable to you. Want to Upgrade?

To: tuck who wrote (468)	10/8/2006 12:26:08 PM
From: tuck	Read Replies (1) \| Respond to of 510

[Interest of major serum protein removal for SELDI proteomic blood profiling] This is a variation of the technique of filtering out some common high abundance proteins via HPLC. >>Proteome Sci. 2006 Oct 5;4(1):20 [Epub ahead of print] Interest of major serum protein removal for Surface-Enhanced Laser Desorption/Ionization - Time Of Flight (SELDI-TOF) proteomic blood profiling. Roche S, Tiers L, Provansal M, Piva MT, Lehmann S. ABSTRACT: BACKGROUND: Surface-Enhanced Laser Desorption/Ionization - Time Of Flight (SELDI-TOF) has been proposed as new approach for blood biomarker discovery. However, results obtained so far have been often disappointing as this technique still has difficulties to detect low-abundant plasma and serum proteins. RESULTS: We used a serum depletion scheme using chicken antibodies against various abundant proteins to realized a pre-fractionation of serum prior to SELDI-TOF profiling. Depletion of major serum proteins by immunocapture was confirmed by 1D and 2D gel electrophoresis. SELDI-TOF analysis of bound and unbound (depleted) serum fractions revealed that this approach allows the detection of new low abundant protein peaks with satisfactory reproducibility. CONCLUSIONS: The combination of immunocapture and SELDI-TOF analysis opens new avenues into proteomic profiling for the discovery of blood biomarkers.<< Cheers, Tuck

To: tuck who wrote (468)	11/18/2006 12:54:50 PM
From: tuck	Respond to of 510

[Counterpoint: SELDI beats ELISA for preclinical in vivo PK studies] >>J Immunol Methods. 2006 Nov 2; [Epub ahead of print] Quantitative detection of therapeutic proteins and their metabolites in serum using antibody-coupled ProteinChip(R) Arrays and SELDI-TOF-MS. Favre-Kontula L, Johnson Z, Steinhoff T, Frauenschuh A, Vilbois F, Proudfoot AE. Serono Pharmaceutical Research Institute, 14 Chemin des Aulx, 1228 Plan-les-Ouates, Geneva, Switzerland. One of the important steps in developing protein therapeutics is the determination of their preliminary PK in vivo. These data are essential to design optimal dosing in animal models prior to progressing to clinical trials in man. The quantitative detection of protein therapeutics in serum is traditionally performed by ELISA, which has the prerequisite of the availability of the appropriate monoclonal antibodies. We have developed an alternative method using polyclonal antibodies immobilized on ProteinChip Arrays and SELDI-TOF mass spectrometry. This method has an advantage over ELISA since it provides simultaneously information on the clearance rate of the protein and it's in vivo processing. We compared these two methods using a RANTES variant, [(44)AANA(47)]-RANTES as the test protein in this study. Using SELDI-TOF mass spectrometry, we were able to establish that the protein is readily oxidized in serum, and moreover is processed in vivo to produce a truncated 3-68 protein, and undergoes a further cleavage to produce the 4-68 protein. These modifications are not identified by ELISA, whilst the serum exposure profiles determined by the two methods show essentially similar protein concentration values.<< Polyclonals are easier to come up with, I guess? Cheers, Tuck