Super-Cheap Paper Microscope Could Save Millions of Lives

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Imagine if clinics in developing countries were equipped with an inexpensive yet durable tool that could help medical personnel identify and diagnose a variety of deadly diseases like Malaria, Chagas disease, or Leishmaniosis? For millions of people around the world waiting to be diagnosed and treated, such a tool could be a life-saver. Manu Prakash, [...]

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Kohler Illumination in Light Microscopy

Köhler illumination is a method of specimen illumination used for transmitted and reflected light (trans- and epi-illuminated) optical microscopy. Köhler illumination acts to generate an extremely even illumination of the sample and ensures that an image of the illumination source (for example a halogen lamp filament) is not visible in the resulting image. Köhler illumination is the predominant technique for sample illumination in modern scientific light microscopy although it requires additional optics which less expensive and simpler light microscopes may not have.

The primary advantage of Köhler illumination is the extremely even illumination of the sample. This reduces image artifacts and provides high sample contrast. Even illumination of the sample is also critical for advanced illumination techniques such as phase contrast and differential interference contrast microscopy.

By adjustment of the field diaphragm the amount of light entering the sample can be freely adjusted without altering the wavelengths of light present, in contrast to reducing power to the light source with critical illumination. Adjusting the condenser diaphragm alters sample contrast. Furthermore altering the size of the condenser diaphragm allows adjustment of sample depth of field by altering the effective numerical aperture of the microscope. The role of the condenser diaphragm is analogous to the aperture in photography although the condenser diaphragm of a microscope functions by controlling illumination of the specimen, while the aperture of a camera functions by controlling illumination of the detector.

Check out the Köhler illumination setup instructions at this link: http://microscopy.berkeley.edu/courses/TLM/condenser/kohler.html

(From Wikipedia, the free encyclopedia. Text is available under the Creative Commons Attribution-ShareAlike License)

The 38th Nikon Small World Top 20 Photomicrographs

Once again, be awed by the images from the winners of this year's Nikon International Small World photography contest. The competition which was launched in 1974, honors those amazing pictures taken through a microscope.

Have a glimpse of the top 20 photomicrographs that were selected for their originality, informational content, and visual impact by a panel of scientists, journalists and optical imaging experts.

First place went to the photo showing the blood-brain barrier in a live zebrafish embryo.

Check out this article on Wired.com.

Incredibly Small: Best Microscope Photos of the Year
http://www.wired.com/wiredscience/2012/10/nikon-small-world-winners/

Taking Photomicrographs Using My Sony Cyber-shot Digital Camera

If you want to take some photographs and videos of microscopic features you are examining under a microscope lens, a simple digital camera is all you need.  No need to have very expensive special equipment to capture beautiful images.

As a malaria microscopy validator I need to record still photos of my findings to be included in the report. I have done these simple steps and techniques in the validation of microscopy results from in vivo therapeutic studies of antimalarial drugs.

JoPas in action

Below is the list of materials and equipment you will need:

1. A compound microscope
2. Digital Camera
3. Specimen in a glass slide
4. 2 stable chairs with backrest

In order to capture a clear photomicrograph shot, the position and level of your digicam must be stable. You can use two chairs with backrest in order for you to have a good control in positioning the digicam. Rest your hands on top of the backrest as seen in the figure below.

Once the specimen is in focus under the microscope, level your digicam lens to the light coming out from one of the eyepiece.  You must be aware of the microscope's eye point or point of focus so that it would be easier to get the distance the camera must be from the eyepiece.  You can check this out by holding a piece of blank paper above the eyepiece.  You will see a light or image projection on the paper.  Move the paper closer or farther from the eyepiece until it is in focus.  That distance is the microscope's eye point.

light projection shown is not yet in exact focus

the exact microscope's eye point showing a clear light projection

Once you see the light or image projection on the display or screen of the camera, lower the digicam slowly until reaching the focal point.  Be sure to keep the position of the image projection at the center of the display as you lower the camera. You will notice that the diameter of the image projection is increasing until the whole field of view is in focus.

 

 

 

 

From there use the zoom function of the camera until the image fills the entire camera's display.  Once adjusted, click the shutter slowly.  You can reduce blurring by setting the self-timer to [2sec] and turning off the flash.  Press the shutter button and hold the camera steadily.  It takes a little practice to hold the camera steady, so take enough shots to make sure you have good ones with the right lighting and focus.

There you have it.  You can now transfer the images into your computer and edit them to your desired appearance.

Microscope Use

To meet the high standards required in microscopy, it is essential to know the proper handling and manipulation of a microscope, its limitations, and the ways to keep it in good working condition. It is the responsibility of the immediate supervisor to ensure that the microscopists are conversant with the operations of the instrument and can follow the standard operating procedures as well as the manufacturer’s instructions in operating, maintaining and storing the microscope for day-to-day use.

a. Parts of the Microscope

b. Care and Maintenance of Microscope

Microscopes are to provide precise results. However, they are sensitive to pressure, movement, temperature, dust, etc. Care and maintenance must always be observed to ensure their effective and efficient use.

     b.1 Requirements for Microscope Use and Preventive Maintenance

The following materials, reagents, and equipment are the minimum requirements for using and maintaining the microscope:

i. Lens Paper 

ii. 70% alcohol (ethyl/isopropyl) 

iii. Aspirator Bulb / Rubber Bulb 

iv. Camel Hair Brush / Soft Make-Up Brush 

v. All-purpose wax/weather wax (not floor wax) 

vi. Soft lint- free cloth (muslin cloth or “pranela”) 

vii. Applicator Stick 

viii. Spare Bulb 

ix. other alternative light source (for areas without electricity) 

x. Equipment Maintenance Record (logbook) Polyvinyl Plastic Cover

     b.2 Cleaning the Microscope by Parts

Optical Parts:

Dry Objectives 

• Blow off dust particles using the rubber bulb and wipe the lens with a lens paper, moving the lens paper across and not circularly. 

Oil Immersion Objectives 

•  Remove oil with lens paper moistened with 70% alcohol if needed, moving the lens paper across and not circularly. 

Eyepiece / Ocular 

• Clean upper lens with a lens paper swab slightly moistened with 70% alcohol then followed by dry tissue swab (see Fig. 3) 

• Wipe in circular motion starting at the center going outward.

Figure 3: Preparation of Lens Paper Swab

Illumination Parts:

The condenser and mirror 

• Clean the same way as the objectives using soft cloth or lens paper 

The support and stage 

• Clean using soft cloth

     

     b.3. Handling and Usage

i. Avoid subjecting the microscope to sudden or severe impact as it is a precision instrument; 

ii. Do not use the microscope where it is subjected to direct sunlight, high temperature and humidity, dust or vibrations; 

iii. When moving the microscope, carry it with one hand under the base and the other hand holding the arm; 

iv. Do not hold the microscope by the stage, stage feed knobs, and observation tube to prevent damage; 

v. Do not move the microscope by sliding it on the table. Otherwise, the rubber feet might be damaged or peeled off; 

vi. Install the microscope on a flat sturdy surface. Never block the air vents on the underside of the base (e.g. placing microscope on a flexible surface such as carpet; 

vii. Cover the microscope when not in use with polyvinyl plastic cover; 

viii. Never leave the microscope without the eyepiece; 

ix. Line up the X 10 objective with the ocular when microscope is not in use; 

x. Never try to dismantle or clean any part of the microscope that is difficult to reach unless you have been trained to do so; 

xi. Clean oil immersion objective after use. Never use ordinary paper or cotton wool to clean the lenses of the microscope. Never use xylene in cleaning any part of the microscope; 

xii. Never touch the bulb and the lenses with bare fingers; xiii. Never exchange parts from one microscope to another. Even some models by the same manufacturer have different specifications.

     b.4 Storage

Fungus cannot grow on glass surfaces when the atmosphere is dry. In these circumstances, it is important to store microscope under dry conditions when not in use. Any of the following methods can be used:

Method 1. Keep the microscope in a warm cabinet with a tightly fitting door and two 25 watt bulbs constantly lighted inside. Depending on the size of the cabinet, you can add more 25 watt bulbs as long as the temperature inside the cabinet is kept constant at 30-35° C but with low humidity. 

Method 2. Keep all lenses and prism heads in an airtight box or dessicator where the air is kept dry by an active silica gel. 

A silica gel is a dessicant that has the ability to absorb water vapor from the air. Self-indicating silica gel is blue when active and turns pink as it absorbs water vapor. When silica gel turns bright pink, it can then be reactivated by heating. After cooling (when it becomes bright blue), it can be used again. 

Method 3. Keep the microscope in a continuously air-conditioned room. However, storing microscope in rooms with air-condition only during the working day are not suitable.

     b.5 Transporting the microscope

It is important that the microscope and its parts are properly secured inside its storage box when the microscope is to be transported from one location to another.

i. Loosen the observation tube clamping knob slightly, rotate the tube by 180o, and tighten the knob; 

ii. Put the transport band; 

iii. Secure the stage and other movable parts; Use various protective materials such as packaging carton, styrofoam or pad inside the storage box.

c. Safety Rules in Using the Microscope

It is important that safety precautions be observed while using the microscope to prevent harm to the microscopists and the facility.

(i) Never work with wet hands, wet body or clothes wet; 

(ii) Do not presume that the circuit is turned off; 

(iii) Do not remove equipment grounds; 

(iv) Do not use defective plugs and cords; 

(v) Always use the correct replacement parts; 

(vi) If the bulb burns out during observation, be certain to cool the defective 

bulb completely before replacement; 

(vii) Keep out of children’s reach especially for the BMMCs.

d. Inspection and Performance Check

This part deals with the routine inspections and performance checks before the unit is put to use and/or being kept after using. A regular and thorough inspection of the microscope will certainly help maintain good operational results and increase its technical lifespan. A weekly inspection of a microscope should include the following points:

i. Ensure that the following parts are clean: 

· all outer surfaces of the instrument - must be free of corrosion or other visible damage; 

· electrical plugs, sockets, cables 

· bulb 

ii. Keep the mounting shoulders of the objectives and the corresponding surfaces on the nosepiece absolutely clean. Otherwise, you will lose the proper positioning of the objectives regarding centering and focus. Be careful not to allow any dust or dirt to get into the objective during cleaning; 

iii. Tighten screws securely; 

iv. Check the that the following are functioning well: 

· the field stop diaphragm move through its full range of opening smoothly and easily 

· all blades of the iris must move properly; 

· the condenser height adjustment knob run smoothly through its full range. Some types have an adjustable brake while others are permanently set; 

· condenser centering screws must move the condenser smoothly and in all directions through its full range; 

· mechanical stage must move the specimen smoothly and without any play through its full range of adjustment in both directions. Check by observing at the microscope’s highest magnification; 

· the slightest touch of the control knob must result in a corresponding movement of the specimen. Keep in mind that one micron of stage movement observed at a magnification of 1000x looks like 1 mm viewed without a microscope and at a distance of 250 mm. Therefore, any disassembly, adjustment, re-greasing, etc. of mechanical stages should be performed only by a trained technician; 

· The nosepiece must rotate smoothly through 360˚, reaching all click-stop positions properly from either side and without any play. Any disassembly at this position interferes with the optical alignment and requires special alignment aids for readjustment; 

v. The fine and coarse focusing knobs must run smoothly through their full range of adjustment. Some types have an adjustable brake (see user’s manual), whereas others are permanently adjusted. Ensure specially that the stage does not lower itself automatically. Do not tighten the brake too much; 

vi. Ensure that the upper surface of the stand and the corresponding mounting surface of the observation tube is clean and free of corrosion. The fastening screw for the tube must hold it securely in place; 

vii. Adjustment of the interpupillary distance of the tube must run smoothly and without exerting undue force; 

viii. All optical surfaces must be absolutely clean. Pay special attention to: light bulb, cover glass on field stop, condenser front lens, objective front lens, upper surface of eye lens; 

ix. Consider the following options in the repair of the microscope. 

· Let user of microscope to attend training on preventive maintenance; 

· Send the microscope for repair to the health maintenance department of the provincial/regional hospitals with personnel trained on preventive maintenance; 

· Send microscope for repair to the DOH-national Health Maintenance Service (HMS) 

· Request CHD or HMS trained staff for repair assistance but provide travel allowance of staff as their counterpart) 

Source: Module on Preventive Maintenance, Care and Basic Troubleshooting on Clinical Laboratory Microscope (Hospital Maintenance Service, Davao)

e. Equipment Maintenance Record

It is important that the history of repair and maintenance of the microscope be documented and properly filed. The Equipment Maintenance Record shall have the following information.

(i) Name of equipment 

(ii) Manufacturer’s name, serial number or other unique identification 

(iii) Origin(from what institution) 

(iv) Date received 

(v) Date placed in service 

(vi) Condition when received (new, used) 

(vii) Details of maintenance carried out 

(viii) Current location, where appropriate 

(ix) Copy of manufacturer’s operating instructions, where available 

(x) History of damage, malfunction or repair (date repaired) 

(xi) Name and signature of technician

Source:  Department of Health - Malaria Control Program Manual of Procedures, Guidelines in the Diagnosis and Treatment of Malaria

Care and Maintenance of a Microscope

The Microscope

Workable Recording and Documentation System for Microscope Preventive Maintenance

It has been said, “work not recorded is work not done”. Therefore, such job must have a corresponding job request / report. Preventive maintenance report indicating among other things such as, the nature of work done, parts used, date of repair / PM, and other important and useful information are usually found.



Equipment Record
Records shall be maintained which include the
following:
 Name of equipment
 Manufacturer’s name, serial number or other unique identification
 Date received and placed in service
 Condition when received (new, used)
 Records of calibration, date of next calibration
 Details of maintenance carried out
 Current location, where appropriate
 Copy of manufacturer’s operating instructions, where available
History of damage, malfunction or repair

Routine Inspection
 Ocular check of the physical surface
 Checking electrical plugs, sockets, cables, bulbs
 Check screws and other mechanical parts
 Check optical elements from mechanical damage and dirt
Check illumination by plugging it to electric power source


Performance Check
 Run the field stop diaphragm throughout its full range
 Move all the blades of iris by its lever control
 Run the condenser height adjustment full range; check its centering screw if it moves the condenser smoothly.
 Check the mechanical stage if it can move the specimen smoothly and without play throughout its full range. Check by observing at the microscope’s highest magnification.
Parameter: 1 micron stage movement observed at 1000X magnification looks like 1 mm viewed without a microscope and at a distance of 250 mm.
 Objectives mounting shoulder, nosepiece must be absolutely clean. If not, centering and focusing are lost.
 Rotate nosepiece through 360º and observe all clicking stop positions from either side without any play
 Run the fine and coarse adjustment knobs throughout their full range of adjustment.
 Make sure that the upper surface of the stand and the corresponding mounting surfaces of the observation tube must be cleaned & free of corrosion.
 Adjustment of interpupillary distance of the tube must run smoothly and without exerting undue force.
 All optical surfaces must be absolutely cleaned. Pay special attention to: light bulb, cover glass on field stop, condenser front lens, objective front lens, upper surface of eye lens. Inspect and clean accordingly.

Microscope Bulb Installation & Replacement

• Setting the line voltage selector switch in position
Ascertain that the line voltage selector switch (1) is set in conformity with the local line voltage. If not, the switch should be set at 100V (110~120V) or 200V (220~240V) correctly by means of a screw driver.

/a

1. Turn the microscope on its side and pull the lamp housing knob (1) to open the lamp housing cover (2)
2. Install the bulb.
• 6V, 20W halogen bulb
Hold the halogen bulb contained in a polyethylene bag to avoid leaning finger prints on the bulb and insert the contact pins into the bulb socket all the way (3).



• 110V/120V 30W tungsten bulb
Insert the tungsten bulb with its mirror portion (4) located at the lower side into the bulb socket; (3) then, pressing it against the socket, rotate the bulb clockwise.



– Before use, wipe off fingerprints or soils on the bulb.
– 110 V bulb for local line voltage 120V or higher.
– After bulb installation, close the lamp housing cover (2) , pushing in the cover knob (1) .
– If the bulb burns out during observation, be certain to cool the defective bulb completely before replacement.
Tungsten Bulb
• Pull power plug
– Place microscope on its side so that rack and knob of the mechanical stage are facing up
• Loosen clamping screw
– Remove lamp socket from spring clamp. Unscrew burnt-out lamp from the socket, and insert new 6V, 5W filament lamp. Wipe off any fingerprints on the lamp bulb.





• To insert new lamp, put lamp socket into spring clamp, turning and shifting it until lamp coil and its mirror image are opposite each other when observing lamp and concave mirror. Insert lamp holder with filament lamp in receptacle so that screw fits into slot. Tighten clamping screw

How to Read Vernier Scales

By Jeffrey V. de Guzman


How to Use a Vernier Scale -