Indian Council of Agricultural Research
(Agricultural Knowledge Management Information System)

ICAR-Indian Institute of Water Management, Opposite Rail Vihar, Chandrashekharpur, Bhubaneswar-751023 Odisha (
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Instrument Details
Instrument/Facility Name: Trinocular Research Microscope (Phase contrast and Florescence illumination)
Make                                   : Carl Zeiss
Model                                  : Axio Scope.A!
Specification   :The trinocular microscope has two eyepieces like a binocular microscope with an additional third eye tube for connecting a microscope camera. They are therefore a binocular with a moving prism assembly in which light is either directed to the binocular assembly of the microscope or to the camera. The microscope allows the user to take pictures, record videos, which can be saved for future references.

Click to ViewVarious contrasting options, the classical methods of brightfield, darkfield, phase contrast –DIC. The transmitted-light beam path for image contrast and homogeneous illumination. Reflector illumination for thick specimens and DIC at high magnifications. For documentation tasks in transmitted-light applications with Axio Scope: the ISCP with additional option for using the interface. The height-adjustable ergotubes with a travel range of 44 mm or the 50-15-50 ergo-phototube with upright correct-side image, which can be adjusted through 50 mm in height and depth at a fixed viewing angle of 15° so as to be as comfortable as possible for your height. The eyepiece setting can also be varied with both tubes, enabling you to gain an additional 50 mm of height.

  Working Principles
Click to ViewThe microscope basically consists of objective lens, ocular lens, lens tube, stage, and reflector. An object placed on the stage is magnified through the objective lens. When the target is focused, a magnified image can be observed through the ocular lens. However, unstained living cells do not absorb sufficient light. Poor light absorption results in very little differences in the intensity distribution in the image. This makes the cells barely, or not at all, visible in the bright field of a microscope. When light passes through cells, small phase shifts occur, which are invisible to the human eye. In a phase contrast microscope, these phase shifts are converted into changes in amplitude, which can be observed as differences in image contrast. However, this label-free technique is strongly dependent on the correct alignment of components in the optical pathway. This alignment can be disturbed by the naturally occurring meniscus effect, causing weak phase contrast. In fluorescence microscopy microbes are stained with a fluorescent dye and then illuminated with blue light. The dye absorbs blue light (shorter wavelength) and emits green light (longer wavelength).

  User Instructions
Microbiology, Live cell tissue culture, cytology, pathology Agricultural Research Microbiological ResearchAdjust image brightness with light intensity control on microscope stand. • Put high-contrast sample into object holder of mechanical stage. • Bring front lens on condenser (if in use) into place (in objectives ≥ 10x) and turn the gear knob for vertical adjustment of the condenser to the top stop. Make sure the stop is adjusted in a way to prevent the condenser from lifting out the sample (adjusting the condenser stop) • On condensers with revolver/modulator disks: turn the knurled to position H (brightfield). • Bring objective 10x in place on nosepiece and focus sample with gear knob. • Close field diaphragm enough to make it visible in field of view (even if blurred). • Lower condenser with gear knob for vertical adjustment until edge of field diaphragm appears sharp. Center the field diaphragm image with both centering screws on the condenser carrier . Open the field diaphragm enough to make the edge of the diaphragm disappear from the field of view. • In order to adjust the aperture (contrast), take an eyepiece from the tube barrel. Looking through the barrel adjust the aperture with the adjusting lever to the size of approx. 2/3 ... 4/5 of the diameter of the objective exit pupil. In most cases this aperture gives the best contrast at almost full resolution and is thus the best compromise for the human eye. • Replace eyepiece in tube barrel. Uncolored biological samples, like bacteria or living cell cultures, are sometimes hard to see in the transmitted light/bright-field due to their translucence. Yet it is completely different when one examines these samples with the transmitted light/dark-field method. One basically illuminates the sample with an illumination aperture which is higher than the one of the objective he is using. In the dark-field, only the diffracted and scattered light portions which are important for the imaging procedure get into the objective, whereas the indirect unaffected light beams are directed past the objective. Thus a resolution of fine structures is achieved which is partially below the resolution capacity of a light microscope. The fine structures now appear bright and incandescent on a dark background.

  Contact Us
Contact No. 06742300060
Email Id

  Trinocular Research Microscope (Phase contrast and Florescence illumination) Charges
Procedure Name
National LAB/R&D

Additional Rs 100/-towards postal charges if result are to be posted
The Demand Draft should be in favour of "ICAR UNIT IIWM Bhubaneswar"
Letter, DD & Samples send to "Director, ICAR-IIWM, Bhubaneswar"