What is a laboratory UV transilluminator

A UV transilluminator is a standard piece of equipment used to analyse and observe DNA, RNA and proteins. It usually consists of an ultraviolet (UV) or visible (blue or white) light source, a glass viewing surface, and a UV-blocking or amber filter cover.

How does a laboratory UV transilluminator work

A transilluminator works by emitting high-intensity UV radiation through the surface of the object being viewed. Specific wavelengths of UV or visible light are emitted onto a glass viewing surface (where agarose or polyacrylamide gels are placed). The transilluminator can be used as a stand-alone system or in conjunction with a gel imager.

Application of UV Transilluminators

The main use of the UV transilluminator is to visualize proteins and DNA after the electrophoresis process on polyacrylamide and agarose gels. It is used for gel electrophoresis, protein fluorescence and gel fluorescence. The following are common experimental applications:

1. DNA/RNA visualisation

After passing nucleic acids through agarose gel electrophoresis, they are stained with fluorescent dyes such as ethidium bromide or SYBR Green. A UV transilluminator camera excites the dye and makes the DNA/RNA bands visible. This helps determine the nucleic acid sample’s size, concentration and purity.

2. DNA, Protein Gel Recording

UV transmission cameras are often integrated into gel documentation systems to image and record electrophoresis results. Photographs of the illuminated bands can be taken for further analysis or publication.

3. Chemiluminescent protein blotting

When proteins are separated by gel electrophoresis and stained with specific fluorescent dyes (e.g., SYPRO Ruby or fluorescein), a UV-transmission illuminometer can help to observe the protein bands.

4. DNA Fragmentation

UV transilluminators are commonly used to extract specific DNA fragments from gels for downstream applications such as cloning or sequencing. UV light makes finding and cutting out the desired DNA bands from a gel easier.

5. Fluorescent dyes

Fluorescent dyes can be used to visualize a variety of fluorescent markers in biological samples, either for gene expression studies or for the detection of labeled probes in hybridization assays.

6. PCR product sizing

7. plaques or colonies on agar plates

8. Colony counting

9. Plant, colorimetric imaging

Selecting a UV Transilluminator for a Gel Imaging System

1. Wavelength range

Standard wavelength: Most UV transilluminators operate in the mid-wave ultraviolet (UV-B) range at 302 nm. This is the ideal wavelength for detecting nucleic acids (e.g., DNA, RNA). Single and dual-wavelength options are also available.

Multi-wavelength options: Some advanced transilluminators offer a choice of different wavelengths (254 nm, 302 nm, 365 nm) for various dyes and application scenarios. The multi-wavelength feature can be used to adapt to different experimental needs flexibly.

2. Transmission area size

The size of the gel determines the effective working area of the transilluminator. Common transmittance area sizes include 21 x 21 cm or larger to accommodate standard gel electrophoresis experiments. If you regularly work with large gels, choose an instrument with a larger transmission area.

3. Light intensity and uniformity

Choosing a UV transilluminator with high light intensity and uniform distribution is important to ensure a consistent fluorescence signal across the gel, thus improving detection accuracy. High-quality instruments typically provide uniform UV illumination over all areas of the gel.

4. Filters and safety

UV transilluminators often come with filters to protect the user from UV light. Some models have removable or adjustable filters to optimize imaging at different wavelengths. UV shielding and protection (e.g., protective eyewear and UV shields) should be provided to ensure safety.

5. Compatibility with gel imaging systems

Ensure that the UV transilluminator chosen is compatible with existing gel imaging systems. Some imaging systems may require specific transilluminator sizes or wavelength ranges, especially if automated image capture is required.
Consider a fully automated gel imaging system, which typically integrates a UV transilluminator, imaging device, and data analysis capabilities that can greatly improve ease of operation and imaging accuracy.

6. Portability and ease of use

If lab space is limited or mobile equipment is required, portability is also a consideration. Some transilluminators are designed to be compact and easy to store and operate.