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.
- Because ethidium bromide is a toxic chemical with strict safety protocols, it is only recommended that you use this dye in a lab with established handling, storage and waste disposal procedures in place. Other users are strongly recommended to use SYBR-Safe instead, which can be handled and disposed of more safely.
- The transilluminator does come with a safety lid for viewing the gel. However, when the lid is not in place, safety glasses must be worn when operating the UVB bulb.
- If you prefer to avoid UVB altogether, we can recommend the blue light LED transilluminators such as the one described in this instructable instead.
Step 1: Materials: Laser cut acrylic parts
Tap holes in the following parts:
- 5-40: Two holes in the enclosure side with the cutout for the power switch
- 8-32: Four holes in the solacryl cover
- 8-32: Four holes in the 0.25" clear lid side part for mounting the hinges
- 8-32: Two holes in the enclosure bottom
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
- Philips screwdriver
- Soldering iron and solder
- Wire clippers
Step 3: Connect AC power to ballast
- Place the power entry and switch into the laser cut back part and secure in place with the two 1/2" long 5-40 machine screws.
- Connect neutral and live wires to ballast as shown in the images
- Solder the neutral wire and live wire to the plug connector as shown in the images.
Step 4: Assemble the enclosure
- Take one of the 1" long 10-32 machine screws and thread it through one of the rubber feet and the corner holes on the bottom enclosure part. On the opposite side of the enclosure, screw in one of the 2.5" long 10-32 standoffs. Repeat for all 4 corners of the enclosure bottom.
- Place the ballast in the middle of the enclosure and fasten down with two of the 1/4" long 8-32 screws. Make sure that the ballast is oriented as shown in the images.
- Put the UVB bulb into the ballast and place the remaining enclosure parts into the slots in the enclosure bottom.
Step 5: Assemble the cover
- Place the lower lid onto the top. It will be secured in place by fitting it over the tabs on the enclosure sides.
- Lay the upper lid onto the lower lid.
- Place the transilluminator glass into the slot on the upper lid.
- Place the UV-transmissive protective plate over the enclosure.
- In each corner screw in the four 1" long 10-32 machine screws to secure all 3 top layers plus transilluminator glass in place.
Step 6: Assemble the hinged safety lid
- Using the Weld-On acrylic glue and applicator, weld the 1/4" acrylic sides onto the 1/8" base.
- Attach the two hinges to the lid using four of the 3/16" long 8-32 machine screws.
- Attach the hinged lid to the top of the enclosure as shown using the remaining four 1/8" 8-32 machine screws.
Step 7: Viewing a gel
- How to Prepare an Electrophoresis Agarose Gel by mmdeaton
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.