The cuvette holds your sample. It is then placed in a spectrophotometer. But the world of cuvettes can be overwhelming and confusing. You may have difficulty deciding which cuvette to use for your experiment. We will first outline the basics of material, then compare different cuvettes to help choose the right one.
As a newbie to fluorometer or spectrophotometer experiments, you might be confused about cuvette selection. If you search for “How do I choose the right cuvette?”, most answers will show that the cuvette material is what you need. UV rays are not able to penetrate most glass cuvettes. However, they can penetrate quartz cuvettes.
Cuvettes available on the market are typically made from plastic, quartz, and glass. However, you can find cuvettes made from other materials listed below.
1.What material are you looking for?
It depends on what wavelength and which solvent you use when measuring the sample.
Wavelength
Cuvettes are often made of transparent materials like optical glass, quartz or sapphire. Every material has its own unique light-passing properties, so it is important to be aware of such characteristics before selecting a cuvette material.
These are the most commonly used cuvettes. They are listed below with the materials they are made from and their appropriate wavelength.
1. Optical Glass Cuvettes
This cuvette material is suitable to the visible spectrum, and has a decent transmission band from 340-2,500nm.
2. UV Quartz Cuvettes
UV-VIS absorbance research requires a UV quartz cuvette. Using a cheaper glass, or plastic cell will cause data to be inaccuracies.
3. IR Quartz Cuvettes
The transmission range of IR Quartz is from 220nm up to 3500nm. It is a good choice when measuring UV VIS.
4. Polystyrene, Polymethyl Methacrylate (PMMA), and Polystyrene
The visible spectrum for PS or PMMA quartz is between 380nm and 780nm. The majority of applications fall within this range, and most do not require the extra UV or IR points you get with other materials.
Each material has its pros and cons. The best one will depend on what your application is.
Quartz material is extremely resistant to temperature and transmission, but it is transparent in both visible and ultraviolet light ranges. This makes it a great choice for measuring UV-light spectrum samples.
The visible wavelengths of light are 380-780 nm for plastic and glass, while the UV wavelengths are 190-340 nm for glass. The plastic and glass cuvettes work well for colorimetric protein analysis or measuring the density of bacterial cultures. However, the UV wavelengths cannot be used to measure concentration and purity of samples.
It is crucial that cuvettes transmit as much light as possible. But if you don’t have the budget or only need to test samples in visible light, then you might consider a Plastic cuvette or Optical Glass cuvette. Plastic cuvettes cost less and are easily disposable.
Transmission of different materials in empty cuvettes
Cuvettes can come in a variety of materials. They can also be assembled with different technology, such as glue, powder fused, or all fused.
If the sample contains an aqueous solution it can be used with any plastic or glass cuvettes.
Working samples
The ideal cuvette material should be transparent to the target beam of light and not interact with samples.
If the sample is aqueous, it doesn’t matter how the cuvette was made. All cuvettes can be used, including quartz or plastic. You can even use URC glued cuvettes that are the most economical.
If your sample contains organic solvents, you should choose stronger cuvettes over the plastic ones like the Quartz and Glass cuvettes.
And you should go with chemical resistant fused (CRF) or high-temperature-resistant (HTR) versions rather than the non-resistant to chemicals (NRC) because the NRC cuvette is assembled with glue, benzene, ethanol, corrosive solutions, or other similar attribute solvents may cause the cuvette to leak because it degrades the bonds between the pieces.
2. Which cuvette type do you require, Fluorescence cuvette or Spectrophotometer?
It all depends on what Laboratory Apparatus is used.
Cuvettes for spectrophotometers are cells with 2 sides optically transparent. The light beam enters from the front and leaves the back of the cuvette along a straight line.
Our QS20/02 and QS37 cuvettes are the best-selling in our cuvettes range for UV VIS Spectrophotometer measurements. They are virtually identical, QS20-2 and QS37. The only difference between QS37 and Type 5 cells is their square corners.
These cuvettes provide the best balance for those looking for high-quality, UV quartz cuvettes. The QS2002 cuvettes offer the complete range of UV quartz material for a very affordable $12.3. This makes it a great choice for labs with limited budgets.
There are some basic spectrophotometer cuvettes. In general, the square-bottomed cuvette costs less than the rounded one. For more information on spectrophotometer cuvettes, click here.
Fluorescence cuvettes consist of cuvettes with four optically polished walls. However, some specialized types have three transparent walls.
QS22-01 is the basic fluorescence quartz cell used for UV VIS measurements. This cuvette features all four windows and is available in UV-grade Quartz.
Some basic fluorometer cell types, such as spectrometer cuvettes are available. However, there is an alternative, which is a round bottom in our fluorescence lines.
3. What length path do you need?
The laboratory apparatus will determine the maximum length of the path you can use. Other factors, such as sample characteristics, volume availability and types or measurements, will also impact the choice of the cuvette length.
A standard spectrometer cuvette‘s light path (or path length) is the distance between cuvette interior walls. It refers to distance between front and back windows. Cuvettes are available in many different lengths. Cuvettes come in a wide range of lengths, with the most common being 10 mm.
We offer path lengths of 1mm up 100mm in addition to the 10mm standard cuvette path. There are light paths that are smaller than 1mm, but they are only for specialized cells such demountable cuvettes (or HPLC flow cuvettes).