Explorer™ LifeSciences (LS)

Scanning Probe Microscope For
Imaging Biological Samples

"Explorer™ LS" is a practical combination of optical and scanning probe microscopy for molecular-level imaging of biological specimens. It provides the capability to visually position the SPM tip exactly over the object of interest, to image samples in liquid under physiological conditions, and to acquire multiple channels of data, simultaneously.

Liquid Cell Schematic

Explorer™ LS is a complete scanning probe microscope system designed for use with Zeiss, Olympus, Nikon and other inverted optical microscopes. The SPM scanning head is the field-proven Explorer™ TMX 2000, featuring our patented Tip Scanning Technology. It is mounted on a base plate adapter, configured to be compatible with the user's existing, or preferred, inverted optical microscope. The base plate includes a sample-slide capture mechanism, sample X-Y positioning, and SPM head mounting.

[Atoms] Explorer™ LS. The Lowest Noise Floor Bio SPM

The design of the Explorer™ LS considers the practical needs and requests of research biologists:

One-Pass Imaging™ with multiple channel data acquisition made possible through precise positioning of the sample and AFM probe

Independent monitoring of sample integrity accomplished with the inverted optical microscope

As little as a 50 micro liter droplet of solution is sufficient for scanning in liquids

Z-scanner body made of chemically inert materials permits scanning in physiological buffers with minimum sample perturbation

100 micron scan range in X and Y axes, 12 micron in Z range with TrueMetrix™ linearized scanning system

Combining the Explorer™ LS with an inverted optical microscope provides research biologists with the best of both worlds: use of their familiar inverted optical microscopes while simultaneously obtaining high-resolution, three-dimensional images of biological specimens in any of the continuum of SPM imaging modes.

Imaging Red Blood Cells

System Configuration

Explorer™ LS is available as a retrofit system for users who already own an inverted optical microscope. Systems consist of the Explorer™ SPM head, mounting base plate adapter with precision 1 micron X-Y translation, laser filter, and system control electronics and software.

Explorer™ SPM head. This includes a 200x off-axis (45°) optical microscope and CCD camera for viewing the tip and sample during tip approach. It is capable of operating in all SPM imaging modes, including lateral force, modulated force, spectroscopy, non-contact, and high-amplitude resonance. In addition to being constructed of chemically inert materials, its scanners are optimized for imaging biological specimens in the molecular regime.

Mounting base plate adapter. Explorer™ LS systems are available with base plate adapters configured for most popular inverted optical microscopes. The functional characteristics are the same for all base plate adapters, the only differences being interface mounting and dimensional variations. Functions include SPM head mounting, sample capture and precision X-Y positioning.

Laser filter. A safety filter assures safe operation when viewing the sample through the optical microscope.

System electronics and computer system. The electronic control unit [ECU Plus] ECU-Plus High Resolution Electronics Control Systemprovides complete digital signal processing and independent feedback and acquisition channels. A Pentium based workstation controls system operation. The operating platform features the standard and proven TMX 2000 operating and data management software.

Explorer™ LS provides serious research biologists with every feature required to perform comprehensive and meaningful imaging of biological specimens.

[Rat Liver Cells] Wet Rat Liver Cells

System Advantages

Explorer™ LS is the result of requirements defined by experts in the field of cell and molecular biology, combined with the firsthand experience of TopoMetrix' staff experimental biologists and scanning probe microscopists. In addition to operating convenience, total system capability and comprehensive SPM features, the following four design objectives were considered and have been met: Operating in liquids. Imaging in liquid eliminates meniscus forces, permits faster scanning and significantly reduces required tip forces which minimizes sample damage. Explorer™ LS permits operating in as little as 50 microliters of liquid without the need for separate fluid-cell hardware. It includes a new scanner system that is constructed of chemically inert materials. As a result, it is capable of operating in liquid without being affected and without causing any detrimental effect to the sample.

[DNA Image] Non-Contact Image of DNA

Accurate positioning of the SPM tip. With the SPM mounted on a special base plate adapter above the sample, the research biologist sees the sample and the SPM probe at the same time. Under familiar visual observation, precision micrometer adjustments are used to position the sample of interest exactly under the SPM tip. Probe tip positioning accuracy eliminates the need for survey scans that can damage the sample. The high resolution of the inverted optical microscope is a natural complement to the imaging capabilities of the SPM. Accurate force / distance and Layered Imaging (tm) experiments are maximized by the use of TrueMetrix™

scan linearization.

Acquiring multi-channel data. Explorer™ LS follows the flexible Open-Architecture design philosophy of the TMX 2000 family of products. As a result, up to eight channels of data can be acquired simultaneously. One-Pass Imaging™ minimizes sample damage by reducing the number of scans required to obtain multiple types of data.

Covalent binding of biological samples to substrates. In order to obtain accurate quantitative images, it is essential that scanning be accomplished with the specimen in liquid, and under physiological conditions when imaging living samples. The development of Explorer™ LS included extensive research into new techniques of firmly anchoring fresh specimens to activated substrates. The success of this effort eliminates the need to dehydrate samples, affix them to substrates and rehydrate them prior to imaging. Recognizing the serious limitations of this procedure, TopoMetrix completely eliminates its requirement with Explorer™ LS LifeSciences SPM.

For the first time, Explorer™ LS provides research biologists with the important capabilities required to probe the molecular level without compromising their sample or their results.

System Operation

Imaging with Explorer™ LS begins by mounting the sample and Explorer™ head on an inverted optical microscope. First, this simple procedure consists of positioning the base plate adapter on the microscope structure. Next, a sample slide is placed on the sample stage of the base plate adapter. The Explorer™ SPM head is then placed on the base plate adapter using a kinematic mounting arrangement for positive alignment.

[Cheek Cell] Human Cheek Cells

The microscopist views the sample using the inverted optical microscope. The sample slide is moved by means o the sample positioning stage X and Y micrometer adjustments to bring the specimen of interest into view and directly under the probe tip. The system is now ready for tip approach and scanning. Explorer™ LS operation is controlled by the system computer. A graphical user interface prompts the user to select the scanning process, parameters and appropriate actions. Once imaging has begun, all raw data are stored in the computer memory. The inverted optical microscope with the safety filter installed can be used during scanning. For added flexibility, TopoMetrix' exclusive SPMTools instrument control language, combined with One-Pass Imaging™, makes it possible to obtain multiple channels of data, simultaneously.

The practical needs of the research biologist were carefully examined before the design of the Explorer™ LS began. The result is an instrument that is easily added to and removed from existing inverted microscopes with minimum interference or procedural adjustment.

For a look at other Biological AFM studies, click this [Bio] Bio Science

Specifications

Probe Stage

Manual X-Y translation stage

X = 1 in. (25mm); Y - 0.5in. (13mm)

Sample size

1 in. (25mm) x 3 in. (76mm) x Olin. (3mm)

Scanner X-Y range

100 micron - linearized, standard

2 micron, optional

Scanner Z range

12 micron, standard

Choice of 0.7,or 5 micron

Optical microscope

Integral, 200X, CCD camera with monitor

Available tips

Pyramidal - 1:1 aspect ratio

NanoSensor - 2:1 aspect ratio

SuperTip(tm) - 10:1 aspect ratio

Computer and Electronics

IBM-compatible Pentium 133MHz CPU (or better) with 1.2Gb hard disk and 32Mb RAM

High-resolution video display card

High-speed DSP card

Serial mouse

SPMLab Image display and analysis software for Microsoft Windows(tm)

Data acquisition software

Advanced Electronic Control Unit (ECU-plus)

Stage electronics

Interconnect cables

* Standard base plates are also provided for use of Explorer™ SPM without inverted optical microscope.

Explorer™, Explorer LS™, One-Pass Imaging™ and SuperTip™ are trademarks of TopoMetrix. Other trademarks and registered trademarks are the property of their respective holders.