A Wellcome Trust equipment grant, awarded in 2009, has allowed the purchase of new spectrophotometers and upgrades to existing equipment.

The following instruments have now been installed .

Horiba Fluorog 3 Lifetime spectrofluorimeter

This modular instrument is fitted with double-excitation and emission monochromators for low stray light levels. The lifetime module operates by the time-correlated single-photon (TCSP) method and uses LEDs at specific wavelengths as the excitation source.

This instrument complements our existing Horiba Fluoromax-4 spectrofluorimeter

Fluoromax-4 spectrofluorimeter

Perkin Elmer Lamda 850 spectrophotometer

This instrument has a double monochromator and can read absorbance values up to 8. It will be used for examining heme and autofluorescent proteins at high concentrations, as well as optical filters for microscopy.

For example, a 488 nm notch filter used for blocking laser light from the emission detector of a microscope would give a false reading in a standard spectrophotometer due to stray light limiting the absorbance reading to about 3.

The sample compartment has a custom-built holder for filters and dichroic mirrors supported at a variable angle (typicaly 45^o) to check for transmission charateristics. The Lambda 850 has a common beam depolariser to overcome polaristaion artifacts introduced by the monochromator.

In addition, a new Perkin Elmer 35 spectrophotomter with a 6 position, Peltier controlled cell holder is available for routine spectroscopic measurements, enzyme assays and DNA melting curves.