Letter from Russell Hart

SeaLite Sciences, Inc.

March 31, 1993

Dear Dick:

I am writing to express my thanks for the skill and help you and everyone at OLIS shows me. As you know I work with the bioluminescent photoprotein, Aequorin, which upon the addition of excess calcium produces a rapid flash of visible light. At SeaLite, we use this protein as a detection device for immunoassays. In my attempts to understand the conjugation chemistry we use, I had fluorescein labeled aequorin. This fluorescein labeled material now produced a different colored emission from the non-labeled protein.

Your instrument, although designed for absorption spectra, was quickly modified to measure the rapid flash produced. In our first experiments we took a few micrograms of the modified aequorin and triggered it. The individual 1 msec spectra looked awful, but the cumulative data showed the two emission peaks very clearly, with the correct positions for both aequorin and fluorescein emission. Our subsequent rapid scanned stopped flow emission spectra of this transient signal showed how good the detection capabilities of the instrument are. We were looking at very small amounts of the protein and obtained individual 1 msec emission spectra with excellent S/N. In a few hours we obtained quality data and spectra that are publication quality.

To anyone looking at low light level chemiluminescent or bioluminescent reactions, or wishing to obtain spectral and kinetic data on transient or precious biological samples the rapid scanner is a must. A wonderful instrument!!

Yours sincerely,

Russell Hart, D. Phil.
Director of Clinical Assays