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66 -- ATOMIC FORCE MICROSCOPE SOL RFQ-NCI-80203-NV DUE 091098 POC Debbie Moore, Purchasing Agent, 301-402-4509, Todd Cole, Contracting Officer, 301-402-4509 The Laboratory of Receptor Biology and Gene Expression, Division of Basic Sciences, National Cancer Institute (NCI) plans to procure an atomic force microscope (AFM), including the magnetic AC and Acoustic AC Mode AFM having a magnetic AC mode sample plate, from Molecular Imaging Corporation, 9830 South 51st Street A124, Phoenix, AZ 85044. The Laboratory of Receptor Biology and Gene Expression is involved in studying native chromatin structure. The structure must be studied at resolutions requiring electron microscopy, while maintaining the material in the hydrated state, rather than a chemically altered state. In order to perform such studies, maximum control over the probe, along with the smallest possible amplitudes and vertical forces on the samples, is required. Molecular Imaging Corporation's atomic force microscope offers maximum control over the probe and the smallest possible amplitudes and vertical forces on the samples. The unique characteristic of the atomic force microscope involves magnetic AC (MAC) mode. MAC mode uses a magnetic field as the cantilever driving mechanism. The important difference between MAC mode and other AC techniques is the advantage in fluid environments. Because of magnetic field driving, the need to drive the cantilever mounting mechanism is eliminated. This direct method of driving the probe results in increased control, which allows for smaller amplitudes and smaller vertical forces on the sample as a result. Therefore, asperities are preserved and spurious responses are eliminated. In addition, this system allows for the lowest contact forces for extremely delicate samples. Therefore, the following attributes are unique to Molecular Imaging's system and required for the above studies: 1.) The required Atomic Force Microscope shall be designed for controlled imaging. To accomplish control as well as high resolution, the probe tip shall be driven directly by a magnetic field. 2.) The operating frequency in fluid shall range continuously from 0 to 70 kilohertz. 3.) The resonant frequency in air shall be from 0 to 120 kilohertz. 4.) Amplitude of oscillation in fluid shall be continuously adjustable from 5 to 30 nanometers at peak to peak amplitude. 5.) The amplitude noise shall be less than 0.1 nanometers Root Mean Square. 6.) The output signal range shall be within a 10 volt output signal noise at less than 0.3%. 7.) Cantilevers shall be driven by an alternating current magnetic field. One of the cantilevers shall have a spring constant of 0.5+-0.1 newtons/meter. 8.) Sample stage shall include a solenoid mounted teflon liquid cell underneath the plate. 9.) Resolution shall be better than 1 angstrom lateral and better than 0.1 angstrom verticle. 10.) Temperature control system shall allow heating to 100 degrees centigrade in liquid. Heating shall be possible while imaging in contact and magnetic AC mode. Molecular Imaging Corporation is the only source known to NCI that can provide an atomic force microscope and meet the above control and resolution requirements. However, if any interested party believes it can meet the above requirement, it may submit a statement of capabilities. Information furnished must be in writing and must contain sufficient detail to allow NCI to determine if the party can meet the requirement. Capability statements must be received in the Contracting Office by 3:00 PM EST on September 10, 1998. If you have any questions, please contact Debbie Moore, Purchasing Agent on (301)402-4509. A determination by the Government not to compete this proposed contract based upon responses to this notice is solely within the discretion of the Government. Information received will be considered solely for the purpose of determining whether to conduct a competitive procurement. Posted 08/24/98 (W-SN240955). (0236)

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