UV-transilluminators are used in molecular biology labs to view DNA (or RNA) that has been separated by electrophoresis through an agarose gel. During or immediately after electrophoresis, the agarose gel is stained with a fluorescent dye which binds to nucleic acid. Exposing the stained gel to a UVB light source causes the DNA/dye to fluoresce and become visible. This technique is used wherever the researcher needs to be able to view their sample, for example sizing a PCR product, purifying DNA segment after a restriction enzyme digest, quantifying DNA or verifying RNA integrity after extraction.
This Instructable tutorial describes how to make a UVB (310nm) transilluminator with a 7 x 7 cm window for viewing ethidium bromide (or SYBR-Safe) stained DNA mini-gels. Once all of the materials are collected, the actual assembly time is approx. 1-2 hours. Some soldering is required.
Step 1: Materials: Laser cut acrylic parts
For the UV transilluminator enclosure and lid, download the design file attached below (svg or PDF file). Laser cut the parts from the material listed in the design file. If you do not have access to a laser cutter, you can send the files to any laser cutting service such as Pololu. Materials for laser cutting can be found at any supplier of acrylic materials (McMaster-Carr, US Plastics etc) except for the solacryl (UV-transmissive) which can be bought from Loop Acrylics.
Tap holes in the following parts:
Step 2: Materials contd: UV bulb, filter and other hardware
1 x 312nm Ushio 9W GPX9E UV bulb Cat # 11_2122, Fotodyne: http://www.fotodyne.com
1 x ballast and G23 lamp holder Cat # 163141.02, Atlanta light bulbs: http://www.atlantalightbulbs.com/
1 x U325C transilluminator glass, 7 x 7 cm, HOYA Corporation: http://www.hoyaoptics.com/color_filter/index.htm
1 x power entry and switch. Cat # CCM1906-ND, Digikey: www.digikey.com
1 x 6' power cord. Cat # 132118, Jameco: www.jameco.com
4 x Plastic Bumper. Cat # 9405K61, McMaster-Carr: www.mcmaster.com
4 x 10-32 standoff, 2.5" long. Cat # 92230A140
4 x 10-32 machine screw, 1" long. Cat # 91249A272
4 x 10-32 machine screw, ½" long. Cat # 91249A263
2 x 5-40 Thread, ½" long. Cat # 91772A128
2 x 8-32 Thread, ¼" long. Cat # 91772A190
8 x 8-32 machine screw, 3/16" long. Cat # 91771A189
2 x Hinges Cat # 1598A52
2 ft x 14 Gauge general purpose wire. Cat # 7587K98
1 x IPS weld-on cement #3 or 4, Cat # 10792, TAP Plastics: www.tapplastics.com
1 x Hypo-type solvent cement applicator, McMaster-Carr, Cat # 25658
Step 3: Connect AC power to ballast
Step 4: Assemble the enclosure
Step 5: Assemble the cover
The top part of the transilluminator includes the transilluminator glass covered with the solacryl UV-transmissive protective cover.
Step 6: Assemble the hinged safety lid
In the final assembly steps we will add a hinged safety lid. The top part of the lid is 1/8" clear acrylic which will block UV light. (Note: you should use safety glasses if you will be operating the transilluminator at any time without the lid.)
Step 7: Viewing a gel
Preparing an electrophoresis gel is a whole other tutorial so for now I would recommend reading this excellent Instructable for preparing the gel:
Once you have your gel prepared, place it onto the transilluminator above the viewing window, put the hinged safety lid down and switch on the transilluminator. At this point you should see your DNA bands.