Sub-micro cells minimise evaporation losses by more than 95% compared to conventional designs by eliminating the headspace volume above the sample using a specially profiled stopper
DNA denaturation studies involve subjecting the sample to temperature cycles to maximum temperatures around 80C, while measuring the change in absorbance using an ultraviolet spectrophotometer.
At these temperatures, particularly with very small samples, evaporation can cause significant measurement errors due to volume and hence concentration changes.
In a normal cuvette, with limited sample available, an empty headspace will exist above the liquid surface, into which evaporation can occur.
The most commonly used, but cumbersome, solution is to cover the sample with a high boiling point, water immiscible solvent to act as an evaporation barrier.
Following a request from a leading spectrophotometer manufacturer, special cells have been developed to overcome this problem.
Starna type 26 LHS sub-micro cells minimise evaporation losses by more than 95% compared to conventional designs.
This is achieved by effectively eliminating the headspace volume above the sample using a specially profiled Teflon stopper.
Cells are available with nominal sample volumes from 10ul to 440ul, with fully heat-fused Suprasil quartz windows as standard.
The black, self-masking cell body can be supplied to accommodate different instrument optical beam heights, very important for maximum energy transmission with the smallest cell apertures.
Also in this range of cells for DNA measurement, Starna supplies a type 64 (160ul) constant temperature cell, that allows for fluid circulation around the sample chamber, which can be changed, when connected to an appropriate thermal circulator.
