Products for Protein Analysis

Ciphergen’s ProteinChip® System is built to analyze proteins captured on ProteinChip Arrays by means of a ProteinChip Reader integrated with ProteinChip Software and a personal computer. The ProteinChip System detects and accurately calculates the mass of compounds ranging from small molecules and peptides of less than 1000 Da up to proteins of 500 kDa or more based on measured time-of-flight. The system is compact enough to fit into almost any lab space, allowing researchers direct access to precision mass analysis of important peptides and proteins from complex biological samples. Although most ProteinChip System applications involve the study of proteins, the system is also capable of analyzing other analytes, including peptides and small molecules. Most protocols involve a short series of binding and washing steps on the array. After preparation of the researcher’s biological sample, a few microliters are placed on the active surface of the ProteinChip Array. Proteins or other analytes are captured on the surface of the array by means of specific surface chemistries or by biomolecules covalently bound to the array. Specific capture of a subset of proteins in the sample occurs through simple chemical interactions or protein-protein interactions. Following binding and washing, an Energy Absorbing Molecule (EAM) solution is applied to the sample retained on the array surface. Application of EAM in organic solvent causes the protein to dissolve into a solution with the EAM. When this solution dries on the array surface, a very crude crystal forms that includes both the protein (or other analyte of interest) and a large molar excess of EAM molecules. The EAM molecules are essential to mediate ionization of the sample. After the crystals of EAM and analyte have formed on the ProteinChip Array, it is placed into the ProteinChip Reader for mass spectrometric analysis. The lid of the reader is opened and the array is placed in the sample handler. The sample handler moves the array up or down to allow reading of a particular sample spot by query with a fixed laser beam. The energy from a single shot of the laser beam is tightly focused on a small area of the spot (“focused laser beam”). Thus each spot contains multiple, addressable positions. The ProteinChip Software is used to precisely control the laser query process.