Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
  • G01Q30/00—Auxiliary means serving to assist or improve the scanning probe techniques or apparatus, e.g. display or data processing devices
  • G01Q30/08—Means for establishing or regulating a desired environmental condition within a sample chamber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y35/00—Methods or apparatus for measurement or analysis of nanostructures
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
  • G01Q20/00—Monitoring the movement or position of the probe
  • G01Q20/02—Monitoring the movement or position of the probe by optical means
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
  • G01Q30/00—Auxiliary means serving to assist or improve the scanning probe techniques or apparatus, e.g. display or data processing devices
  • G01Q30/04—Display or data processing devices
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
  • G01Q30/00—Auxiliary means serving to assist or improve the scanning probe techniques or apparatus, e.g. display or data processing devices
  • G01Q30/08—Means for establishing or regulating a desired environmental condition within a sample chamber
  • G01Q30/10—Thermal environment
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
  • G01Q30/00—Auxiliary means serving to assist or improve the scanning probe techniques or apparatus, e.g. display or data processing devices
  • G01Q30/08—Means for establishing or regulating a desired environmental condition within a sample chamber
  • G01Q30/12—Fluid environment
  • G01Q30/14—Liquid environment
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01Q—SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM]
  • G01Q60/00—Particular types of SPM [Scanning Probe Microscopy] or microscopes; Essential components thereof
  • G01Q60/24—AFM [Atomic Force Microscopy] or apparatus therefor, e.g. AFM probes
  • G01Q60/38—Probes, their manufacture, or their related instrumentation, e.g. holders
  • G01Q60/42—Functionalisation

Definitions

• the present invention generally relates to devices and methods for studying biological systems, and more particularly to those enabling scanning probe microscopic and, in particular, force spectroscopic investigations.
• Biological systems and their processes are based on molecular interactions. Molecular forces in biological systems differ from other molecular systems, in particular with regard to chemical reactions and physical changes of an overall system. However, statements about molecular interactions in biological systems are the prerequisite for analyzing such systems and making further statements.
• lateral resolution is to be understood as the resolution in a plane of a surface of a biological system to be examined, while the resolution perpendicular to this plane is referred to as vertical resolution.
• scanning probe microscopy approaches include raster-force microscopic approaches, such as, for example, scanning force microscopy (SFM) or atomic force microscopy (AFM).
• SFM scanning force microscopy
• AFM atomic force microscopy
• v ⁇ force spectroscopy vs denotes determined moleku ⁇ lare forces a sample using a probe, with which the sample is scanned to, for example, interactions between individual molecules to characterize quantitatively.
• the probe is scanned over the surface of the sample, the lateral and vertical positions and / or deflections of the probe being ascertained Due to the elastic properties of the probe and in particular of the cantilever, movements of the probe relative to the specimen are possible On the basis of detected lateral and vertical positions and / or deflections of the specimen, molecular forces on the part of the specimen and its surface topography are determined ,
• movements of the sample are determined by means of optical measuring devices which have resolutions in the range of 0.1 nm and enable detection of forces of a few pN.
• the surfaces of the sample and the probe of an atomic force microscope are brought into contact with one another in such a way that a force acting therebetween is set to a predetermined value (eg 50-100 pN). Thereafter, the sample will laterally move the probe relative to each other so that a raster scan of the surface sample by the probe will occur. In this case, the sample and / or the probe are also moved vertically, in order to keep the intermediate force at the predetermined value. Movements of the sample and the probe relative to each other can be effected by a piezoceramic-comprising arrangement.
• An advantage of atomic force microscopy is that biological samples can be examined in buffer solutions at physiologically rele vant temperatures (eg between 4 ° C and 60 ° C).
• a probe S is used to probe the surface of a biological sample BP.
• the probe S may be considered as comprising a probe tip Sp "suspended" by a spring C. With movements of the probe S and the sample BP relative to each other (for example along the path W), the probe S and the sample BP are moved relative to each other in the vertical direction so that the deflection of the spring C is constant, depending on the respective surface topography is.
• the object of the present invention is to provide means for eliminating the disadvantages of known scanning microscopy approaches, in particular with regard to personnel expenditure and time expenditure, and to provide the measurements required for a sound examination of biological samples. Furthermore, the present invention is intended to make it possible to use data obtained in scanning probe microscopy comparisons with the prior art in an improved manner to be able to.
• the present invention provides an apparatus for scanning probe microscopy and a method for performing a scanning probe microscopic measurement according to independent claims 1 and 32, respectively. Preferred embodiments will become apparent from the appended claims, the following description and the drawings.
• the device according to the invention is used for scanning probe microscopy and comprises a scanning microscopy measuring device which comprises a measuring probe for scanning microscopy measurements and a sample carrier for arranging a sample to be measured by scanning microscopy. Furthermore, a control device and / or an evaluation device is provided.
• the controller is system integrated, i. as an integrable component of the device according to the invention with the ra ⁇ stermikroskopischen measuring device connected, andiserich ⁇ tet, the measuring device for performing a rastermikro ⁇ scopic measurement according to predetermined control parameters au ⁇ automatically control.
• the evaluation device is also system-integrated connected to the scanning microscopic measuring device, thus forming an integral part of the device according to the invention, and is adapted to automatically evaluate measurements by means of rastermikroskopi- see measuring device according to predetermined evaluation parameters.
• the device according to the invention provides a platform for automatically carrying out and / or analyzing examinations of biological samples by means of raster probe microscopy. Furthermore, the device according to the invention makes it possible to carry out measurements on the respective biological gische sample or adapt their system by appropriate control parameters and / or evaluation parameters are used. An advantage, for example, based on this is that such measurements can be carried out essentially without personnel all day and simultaneously analyzed.
• control device and / or the evaluation device is set up to identify measurements of the measurement and / or evaluation device indicating data for determining input parameters or parameter sets of the measurement.
• This feature can also be referred to as the feedback of measurements of the measuring and / or evaluation device indicating data as control and / or evaluation parameters.
• the identification of parameters or parameter sets can be carried out using iterative search algorithms.
• the control device and the evaluation device are logically connected to one another.
• the evaluation device analyzes the force-spectroscopic data during an experiment. When a significant number of data is reached, the next experimental parameters are set and the experiment is continued.
• the experimental parameters can be changed so that, for example, certain changes in the measured forces (and the energies and bonding constants determined therefrom) are examined in more detail. So it becomes e.g. it is possible to automatically investigate the areas of molecular interactions of interest to the user.
• This embodiment of the device according to the invention makes it possible to classify measurements and samples, to compare measurements on a sample with one another, to develop and / or to use optimized measurement strategies, and to optimize measurement strategies used.
• the device comprises a data storage device for storing the data generated by the evaluation device, which results from an evaluation of measurements by means of the scanning probe microscopic measuring device.
• a data storage device for storing the data generated by the evaluation device, which results from an evaluation of measurements by means of the scanning probe microscopic measuring device.
• This embodiment makes it possible, for example, to set up a database with information about measurements on samples to be surveyed by means of a scanning probe microscope, which can be used before, during and after an ongoing measurement.
• the data storage device can also be used for returned measurement results, whereby comparisons are also provided with information already present in the data storage device.
• the data storage device is designed, the predetermined control parameters and / or the predetermined
• the probe comprises a resilient unit.
• the spring-elastic unit may have an overall elastic design or have a resilient area.
• a resilient unit for example, a (katra ⁇ gender) boom or measuring beam (cantilever) can be used.
• the measuring device is capable of evaluating forces acting on the measuring probe.
• the measuring device interacts with the sample and resulting forces acting on the probe, using an optical measuring system (eg laser beam system). Deflection system, beam bouncing) and / or piezoelectric Ef fects and / or _ _
• the device according to the invention can also comprise a unit for generating a light field acting on the measuring probe and / or electric field and / or magnetic field.
• the field (s) may be static or dynamic fields, with alternate operation between static and dynamic.
• a spring which preferably has a length in the range between 1 and 400 micrometers, and / or an elastic cantilever (cantilever) is provided as the spring-elastic element.
• control device is able to control the spring-elastic unit in such a way that the measuring probe is vibrated with a predetermined amplitude. For example, amplitudes in the range between 0.1 and 2000 nanometers are provided.
• the device according to the invention may comprise a power generating unit, which may be associated with the measuring device and / or the control device.
• control device is able to control the power generation unit automatically so that changes of an effective quality factor (Q factor) for the measuring probe can be achieved by applying corresponding forces to the resilient element.
• Q factor effective quality factor
• the use of the force-generating unit is particularly preferred if the measuring probe is to vibrate.
• the evaluation device can be set up, such changes in the form of resonance shifts and / or
• the measuring device comprises a probe positioning unit in order to position the measuring probe in all translational and / or rotational axes of the room.
• the control device can automatically position and / or move the measuring probe by controlling the positioning unit in accordance with predetermined probe positioning parameters.
• probe positioning parameters that include:
• Movements of the probe for the raster scanning of a sample to be arranged on the sample carrier such Be ⁇ movements lateral movements and / or movements in the range between 0.1 nanometers and a few millimeters, preferably in the range between 0.1 nanometers and 500 microns, comprising movements the measuring probe in the vertical direction, it being provided that such movements may be in the range between 0.01 nanometers and 50 microns,
• Movements of the measuring probe in the vertical direction as a function of a predetermined minimum distance between the measuring probe and the sample it being possible to use a distance control, for example a PID and / or a phase-logic control, for motion control, a maximum time duration for a contact of the probe with a sample to be arranged on the sample carrier, a maximum contact frequency of contacts of the Messson ⁇ de with a sample to be arranged on the sample carrier, a maximum and / or a minimum Meßsondengeschwin ⁇ speed for movements of the probe relative to a a sample to be arranged on the sample carrier, a maximum and / or a minimum distance between the measuring probe and a sample to be arranged on the sample carrier, a predetermined, between the probe and a sample to be arranged on the sample carrier to be held constant force, for example, in the range between 0, 1 and 3000 pN can be a maxima le and / or a minimum tensile force of the measuring _ _
• a maximum and / or a minimum pressure force of the measuring probe on a sample to be arranged on the sample carrier a maximum and / or a minimum tensile force change rate for from the measuring probe to a sample to be arranged on the sample carrier acting tensile forces, a maximum and / or a minimum pressure force change rate for pressure forces acting on a sample carrier by the measuring probe, a maximum and / or a minimum shearing force of the measuring probe on a sample to be arranged on the sample carrier, and / or a maximum and / or a minimum shearing force change rate for shearing forces acting on a sample to be placed on the sample carrier by the measuring probe.
• a first detector unit is vor ⁇ seen, the positions of the probe and / or movements of the probe, preferably also the deflection, and / or forces acting on the probe regularly, e.g. repetitive with a frequency of a few tens or a few hundred kHz can detect.
• the control device is preferably designed to automatically control the first detector unit in accordance with predetermined detection parameters.
• the first detector unit comprises position sensors for detecting the position and / or movement of the measuring probe.
• position sensors for detecting the position and / or movement of the measuring probe.
• LVDT sensors LVDT sensors, strain gauges, optical sensors, interferometric sensors, capacitive sensors can be used for this purpose.
• an optical beam deflection detector for detecting the deflection of the measuring probe is provided.
• the first detector unit is connected to the control device at least in this respect.
• control device is able to control the first detector unit in accordance with predetermined detection parameters, which include a predetermined detection rate with regard to individual, several and / or all variables to be detected, and / or a frequency at which the first detector unit positions - Ons, motion and / or force measurements should perform.
• predetermined detection parameters include a predetermined detection rate with regard to individual, several and / or all variables to be detected, and / or a frequency at which the first detector unit positions - Ons, motion and / or force measurements should perform.
• the evaluation device can automatically evaluate variables detected by the first detector unit. This can be done analytically and / or statistically.
• the evaluation device can be set up in such a way that variables detected by the first detection unit are classified. It is preferred that classified quantities or data indicating this to the evaluation device, as explained above, be fed back into the measuring process, for example to identify special parameter sets of the measurement.
• the measuring device comprises a sample carrier positioning unit in order to enable positioning of the sample carrier.
• the control device can be embodied such that the sample carrier can be automatically positioned and / or moved by means of control of the sample carrier positioning unit in accordance with predetermined sample carrier positioning parameters.
• sample carrier positioning parameters used are those comprising:
• Movement of the sample carrier for the screened scanning of a sample to be arranged on the sample carrier sample by the probe wherein movements can occur laterally and / or may be in the range between 0.1 and 500 microns, _ n _
• a maximum time duration for a contact of a sample to be arranged on the sample carrier with the measuring probe a maximum contact frequency of contacts of a sample to be arranged on the sample carrier sample with the probe, - a maximum and / or a minimal Probenenoughgeschwin ⁇ speed for movements of the sample carrier relative to the measurement ⁇ a probe, a maximum and / or a minimum distance between ei ⁇ ner to be arranged on the sample carrier sample and the probe, - a predetermined, between a an ⁇ on the sample carrier an ⁇ speculating sample and the probe to be held constant force, for example, in the range between 0.1 and 3000 pN, a maximum and / or a minimum tensile force on a sample to be arranged on the sample carrier by the probe, a maximum and / or a minimum pressure force on a sample carrier to be arranged sample by the probe, a maximum and / or a minimum rate of tensile change for one on the sample a maximum and / or a minimum
• the sample carrier positioning unit comprises a piezoelectric actuator and / or a linear drive, which may be, for example, a voice coil drive (voice coil drive).
• a piezoelectric actuator and / or a linear drive which may be, for example, a voice coil drive (voice coil drive).
• the sample carrier positioning unit can additionally be designed such that "large" positioning movements and / or movements of the sample carrier are made possible, for example in the range between 100 nm and 30 cm.
• the advantage of such a sample carrier positioning unit with coarse positioning is that pre-positioning and larger movements can be carried out quickly. Exact positioning and movements can then join.
• the sample carrier positioning unit is assigned position and / or movement detection sensors that provide information for controlling the sample carrier positioning unit, for example using a closed control loop.
• the above-mentioned position sensors and / or further sensors can be used.
• the measuring device comprises a sample chamber in which a fluid can be received, with which a sample to be arranged on the sample carrier is to be surrounded.
• surrounded is meant that at least the region of the sample to be examined is surrounded by fluid, for example a certain surface of the sample.
• the control device can be designed to monitor predetermined fluid parameters for the respective fluid used and, if necessary, to adjust them.
• fluid parameters for example, those are provided which comprise: a predetermined temperature, a predetermined temperature profile, a predetermined pH value, a predetermined pH profile a predetermined electrolyte content, a predetermined electrolyte content profile, a predetermined volume flow, a predetermined volume flow change, a predetermined level of fluid, and / or a predetermined amount of biological and / or chemical markers.
• markers When using a predetermined amount of biological and / or chemical markers as fluid parameters, quantities for fluorescent markers and / or radioactive markers may be predetermined.
• markers are used which are chemically and / or biologically functionalized, ie have selective properties with respect to the sample to be examined.
• a delivery unit with which fluid (e.g., buffer solution (s), reagent (s)) to be delivered to the sample chamber can be provided.
• the control device can be designed such that the supply unit is monitored and, if appropriate, controlled in such a way that predetermined boundary conditions for the respective fluid, preferably also its composition, are maintained in the sample chamber. For example, certain reagents are automatically mixed together to adjust fluid parameters such as pH, etc.
• the supply unit allows a supply of fluid to the sample carrier in the area in which samples are to be arranged during measurements. It is further preferred that the Zubigein ⁇ unit is automatically controlled by the control device.
• the supply unit may comprise a pump and / or a multi-channel pump.
• a second detector unit For monitoring fluid in the sample chamber and / or given boundary conditions for the respective fluid, a second detector unit may be provided which is capable of detecting a current fluid level in the sample chamber.
• the control device can be designed so that in response to the second detector unit detected Pluidpegel the first Zufuh ⁇ purity is automatically controlled.
• a temperature chamber which surrounds at least the measuring probe and the sample carrier. It is further provided that the temperature chamber also surrounds further components of the measuring device, such as, if present, the force generating unit, the probe positioning unit, the sample carrier positioning unit, the sample chamber, the first supply unit and / or the second feed unit referred to below. In this case, it is preferable for the temperature chamber to be controlled by the control device in accordance with predefined temperature parameters.
• the Steuereinrich ⁇ device is able to control the temperature chamber so that a vor ⁇ given temperature is maintained and / or at least a predetermined temperature profile is achieved.
• the control of the temperature chamber it is possible for the control of the temperature chamber to occur so that constant temperature periods alternate with periods in which temperature changes take place.
• the scanning microscopic measuring device is a force-microscopic measuring device, preferably for detecting force-displacement curves. From this information on interactions and binding forces of single molecules can be gained.
• the measuring device also comprises an optical detection unit, preferably a unit based on fluorescence and / or transmitted-light microscopy technology (for example DIC and / or phase contrast, bright field and / or dark field).
• an optical detection unit preferably a unit based on fluorescence and / or transmitted-light microscopy technology (for example DIC and / or phase contrast, bright field and / or dark field).
• Fig. 1 is a schematic representation of the principle of a raster power microscope (AFM),
• FIG. 2 schematically illustrates an embodiment 1 of the scanning probe microscopy apparatus according to the invention
• Fig. 3 shows an illustration of a measuring probe arrangement for use in the device according to the invention.
• embodiment 1 comprises a raster probe microscopic measuring device 2, such as an atomic force microscopic measuring device (AFM), which comprises a measuring probe 4 for atomic force microscopy and force microscopy measurements and a sample carrier 6, on which for carrying out a measurement, a biological sample 8 is arranged.
• a raster probe microscopic measuring device 2 such as an atomic force microscopic measuring device (AFM)
• AFM atomic force microscopic measuring device
• AFM atomic force microscopic measuring device
• the measuring probe 4 is constructed as a cantilever, which serves as a spring-elastic unit of the measuring probe 4 and integrated in the same construction at its free end or has a special tip (not designated) connected to it.
• the illustration of FIG. 2 shows only one measuring probe. However, it is intended to use more than one measuring probe 4 in the measuring device 2.
• the measuring device 2 may have two, four, six, eight and up to a hundred or more measuring probes 4.
• the measuring device 2 may have two, four, six, eight and up to a hundred or more measuring probes 4.
• cantilever chips By constructing a plurality of measuring probes to be used in the measuring device 2, for example so-called cantilever chips can be used.
• FIG. 3 shows an electron micrograph of a can-tilever chip which has eight spring-elastic units 4 ⁇ ,... 4s in the form of cantilevers. Using nanotechnological approaches, such chips with a hundred or more cantilevers are possible.
• the measuring device comprises a force-generating unit (not shown) cooperating with the measuring probe 4 and in particular with its spring-elastic unit.
• the force-generating unit makes it possible, for example, to move the measuring probe 4 in such a way that a quality factor (Q-factor) desired for a measurement is achieved.
• the measuring device has a probe positioning unit (not shown) in order to position the measuring probe 4 relative to the sample 8.
• the probe 4 can be correspondingly positioned and moved by means of the probe positioning unit.
• the first detector unit 12 is constructed as an optical detector and comprises a radiation source 14, for example a radiation source emitting laser light, and a receiver 16 which receives light from the radiation source 14 after interaction with the measuring probe 4.
• the radiation source 14 irradiates the measuring probe 4 with For example, in the area of their free end. Interactions, in particular reflections of the light from the radiation source 14 are detected by the receiver 16 in order to conclude, after evaluation, on positions and movements of the measuring probe 4.
• the measuring device 2 further comprises a Probenippopositio- nierhimssen 10, the one component may be the same 'carrier constructional unit provide the samples inte ⁇ grated or.
• the sample carrier 6 and the sample carrier positioning unit 18 can also be designed as separate components.
• the sample carrier positioning unit 18 uses a piezoelectric actuator which enables movements and positions of the sample carrier 6 and thus the sample 8 arranged thereon in the room.
• a sample chamber 20 surrounds the measuring probe 4 and the sample 8 or at least? the area of the sample 8 to be examined, for example its upper surface.
• the sample chamber 20 is closed in a fluid-tight manner, apart from the inflows and outflows described below, and thus provides a closed space in relation to surrounding areas.
• the sample chamber 20 can altogether serve to receive fluid or, as shown in FIG. 2, have a fluid chamber 22 for this purpose, which is designed such that the measuring probe 4 and the
• Sample 8 or whose area to be analyzed are surrounded by fluid.
• the second detector unit 24 is embodied here as an optical measuring unit which comprises a light source 26, for example in the form of a laser light emitting light source, and a receiver 28 which receives light from the light source 26 after interaction with fluid in the sample chamber 20. Statements about the fluid level in the
• Sample chamber 20 are possible based on the light that receiver 28 receives.
• the sample chamber 20 is connected to a supply line 30, via which fluid can be supplied to the sample chamber 20. Fluid can be removed from the sample chamber 20 via a discharge line 32.
• the supply line 30 is connected on the input side to a supply unit 34, via which individual, several, mixed and mixed fluids can be supplied to the supply line 30 and thus to the sample chamber 20.
• the supply unit 34 comprises for this purpose one or more pumps or multi-channel pumps and devices (not shown) for mixing and mixing fluids. Via feed line 36... 36 n , the feed unit 34 receives fluid from fluid reservoirs (not shown). In the embodiment 1, any desired, desired and / or required fluids in an analysis of the sample 8 are supplied via the supply unit 34, for example buffer solutions and reagent substances.
• the temperature chamber 38 ensures a close to the environment at least in terms of temperature.
• the embodiment 1 further comprises a control device 40 and an evaluation device 42.
• the control device 40 serves to control the components arranged in the temperature chamber 38 and the temperature chamber 38 itself.
• connections 44 and 46 between the control device 40 and the supply unit 34 or the sample unit are representative of the connections required for this purpose.
• carrier positioning unit 18 shown. - -
• the evaluation device 42 receives from all the components enclosed by the temperature chamber 38, if so designed, and from the temperature chamber 38 itself, data, measuring signals and the like in order to determine the respective current operating state or state. To be able to determine and evaluate current measurement results. '
• connections 48. 50 and 52 between the evaluation device 42 and the supply unit 34, the sample carrier positioning unit 18 and the second detector unit 24 are shown.
• the embodiment 1 comprises a data storage device 54, which is connected to the control device 40 and the evaluation device 42.
• the data storage device 54 serves to store current data obtained by the evaluation device 42, measurement signals and the like, current data provided by the evaluation device 42, parameters that can be used by the control device 40 to control the embodiment 1, and others, data described below.
• the data storage device 54 is set up in such a way that it is used as a database in which evaluated data and data of third parties acquired with the embodiment 1 can be stored.
• the control device 40 controls not only the actual force spectroscopic experiment, but also all experimental conditions, such as temperature, the pH effective for the sample 8, the electrolyte interacting with the sample 8, and the addition of pharmaceutical, biochemical and chemical reagents. Furthermore, the control device 40 checks at predetermined times, at predetermined time intervals or continuously for the measurement effective parameters and boundary conditions and controls the measurement such that specifications for the measurement are met.
• the evaluation device 42 analyzes the force spectra detected in the measurement by means of the measuring probe 4 with respect to the sample 8 and can analyze the force spectra. Depending on this, it is possible, for example when a setpoint is reached, to terminate the current measurement and to initiate a new measurement with changed specifications (eg environmental conditions).
• the control device 40 and the data provided by the evaluation device 42 also make it possible to perform iterative measurement cycles in order to determine boundary conditions that favor certain interactions.
• the measuring probe 4 is scanned over the sample 8, wherein (biological) molecules on the surface of the sample 8 can be detected on the basis of interactions between the measuring sonometer 4 and the sample 8.
• certain contact times and / or contact frequencies between the measuring probe 4 and the sample are required. These parameters are set by the control device 40, monitored and corrected if necessary. In this case, it may be advantageous, in particular to carry out a completely automated measurement, to prepare sample 8 in an optimized manner. Further details on this can be found below.
• control device 40 controls all relevant experimental conditions, such as maximum and / or minimum pressure and / or tensile forces between the measuring probe 4 and the sample 8, speeds with the movements relatively between the measuring probe 4 and 8, the number of measuring points (resolution) and maximum and / or minimum distances between the measuring probe 4 and the sample 8.
• the data obtained may be assigned to a data set. Further data sets can then be created and compared with each other under changed experimental conditions. This makes it possible to analyze different biological and / or medically relevant experimental conditions with regard to their influence on molecular interactions.
• thermo changes In order in particular to minimize the thermal drift in the case of changes in experimental conditions, such as, for example, changes with respect to buffer solutions which interact with the sample 8, the temperature chamber 38 is provided. Furthermore, a heating or cooling element (for example Peltier element) can be used in order to control the temperature of the sample 8 itself. Such a heating or cooling element can be arranged, for example, under the sample carrier 6.
• a heating or cooling element for example Peltier element
• Biomolecular interactions usually depend heavily on the prevailing physiological environmental conditions. These should therefore be controlled during a measurement and controlled in such a way that desired environmental conditions are maintained or native states of the sample 8 are stimulated. For example, during a measurement, it is provided to control the level of a buffer solution present in the sample chamber 20 at predetermined time intervals by means of the second detector system 24, or to continuously control the supply unit 34 and possibly to operate the supply unit 34 in such a way maintaining or attaining a desired level. In this way it is possible, for example, during a measurement to reduce the buffer level. "*
• pH fluctuations and changes in terms of electrolytes used and other substances interacting with the sample 8 can be controlled and optionally controlled.
• drying and desalting can also be prevented.
• fluid movements for example, vortices
• fluid movements in the sample chamber 20 can cause vibrations of the measuring probe 4.
• the control device 40 to interrupt an ongoing measurement if such disturbances are to be expected and / or such disturbances are detected or predicted by the evaluation device 42.
• the speed with which a measurement can be carried out plays an essential role. However, faster measurements can affect their quality.
• the invention allows the measuring probe 4 to be moved and / or positioned at relatively high speeds. It is intended to use different speeds for moving and / or positioning the measuring probe 4 during a measurement at different and / or identical measuring points. This makes it possible, for example, to make more detailed statements about molecular interactions from force spectra acquired at different speeds (eg force distance curves).
• measurements can be optimized by increasing the resolution at which force spectra are acquired. This can be achieved by minimizing the smallest force that can be detected by the measuring probe 4. The smallest detectable force depends inter alia on the elastic property of the measuring probe 4. In order to achieve the smallest possible detectable forces, it is therefore necessary to use measuring probes which have as soft a spring as possible. _ -
• Another possibility is to increase the pull-up speeds of the probe.
• High velocities can in particular cause hydrodynamic flows and undesirable movements of the measuring probe 4 resulting therefrom.
• increased noise may occur in the measurement data, thereby degrading the sensitivity to low forces between probe 4 and sample 8.
• Such measuring probes show a significantly improved hydrodynamic behavior compared to conventional measuring probes and allow significantly higher drawing speeds. However, such probes are deflected less. Therefore, in the invention, as the detector system 12, a possible high-resolution optical detection system with special optics is used.
• the measuring probe 4 is set into low-amplitude oscillations (eg 0.1-10 nm) during a measurement.
• low-amplitude oscillations eg 0.1-10 nm
• the probes surrounded by buffer fluid usually have low Q factors.
• molecular interactions are detected by resonance shifts or resonance maxima of the probe.
• Resonance properties of the probe are proportional to the Q-factor, with a low Q-factor leading to a broad resonance maximum. Therefore, the sensitivity of force detection is low with low Q-factor.
• dissipative interactions for example caused by hydrodynamic flows of a fluid surrounding the measuring probe, influence the spring-elastic properties of the measuring probe (eg damping constant).
• Form 1 it is provided to increase the Q-factor by applying an external force to the measuring probe 4 by means of a positive feedback loop.
• the Q factor can be improved by three or more orders of magnitude, with the force sensitivity being in the range of a few pN.
• the force curves are processed so that they can be compared with each other. This can be done, for example, by defining a common zero line (reference values) and a corresponding displacement and / or extension of the individual force curves.
• the entire measurement can be analyzed statistically to obtain, for example, in folded proteins insight into the probability distribution of individual deployment processes and forces required for deployments.
• the force curves can be classified, superimposed on each other and averaged.
• the length of the respective force curve and the number and position of force maxima present there can be used.
• the length of a force curve indicates the area over which interactions occur.
• the number and position of force maxima permits statements about collective and / or singular interaction processes.
• a classification of force curves, the averaging of force curves of a common class and thus mutually related or comparable interaction processes as well as a subsequent statistical analysis allow comparisons of interaction processes of different samples under the same experimental conditions and identical or comparable samples with the same experimental Conditions.
• three mutants of the same receptor which differ in a point mutation can be identified on the basis of their interaction spectra and compared with one another. It is also possible to make statements about the influence of mutations on local interactions of a protein and of the protein with other molecules.
• the data storage device 54 By means of the data storage device 54 it is possible to create a database for force spectra, for example to characterize typical interaction processes of different samples and different experimental conditions. For accesses to a database of the data storage device 54, it is intended to use different search strategies. For example, structural data of a depleted protein can be used to localize structurally related proteins and compare their unfolding pathways. In order to compare different deconvolution spectra, it is possible to also evaluate data of the data storage device by means of the evaluation device 42 in order, for example, to superimpose and compare different force spectra. This makes it possible to make statements about interdependencies of interaction conditions of experimental conditions. Also, interaction processes of different samples can be judged as to whether their interaction processes occur indicate comparable, similar or identical properties of the samples.

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