Laboratory of Molecular Biophotonics

Hisayoshi Takamoto

Shinji Ohsuka

Kenichi Kasai

Hiroyuki Matsumoto

Kiyohito Shimura

Provided are isoelectric point(pI) markers for isoelectric focusing with fluorescence detection. The markers are fluorescence-labeled oligopeptides which comprise a fluorescence dye bonded chemically to the amino group of N-terminal amino acid of oligopeptide. The marker shows its unique and narrow pI band(peak) in electrophoresis or isoelectric focusing. The markers can be designed to have appropriate pI value, and cover wide range of pI (3&lt;pI&lt;11). Further, the markers have good storage stability. The markers can be preferably applied to the capillary isoelectric focusing with fluorescence detection due to their sharp and narrow band with strong emitted fluorescence.

Isoelectric point markers for isoelectric focusing with fluorescence

When incident light is incident to a photodetector, photoelectrons are emitted therefrom and then multiplied to output an electric current signal. This current signal is integrated over a predetermined period of time in an integrator to be converted to a voltage signal. This voltage signal is converted to a digital signal by an AD converter. This digital signal is supplied to a histogramming memory, which generates a pulse height distribution of voltage signal. Based on a pulse height distribution N(h) generated with incidence of measurement-object light to the photodetector, a pulse height distribution of single photoelectron events p.sub.1 (h) generated by a generator of pulse height distribution of single photoelectron events, and pulse height distributions of k-photoelectron events p.sub.k (h) (k=2, 3, . . . ) calculated and generated in a generator of pulse height distributions of k-photoelectron events, an estimating unit estimates a distribution of numbers of photoelectrons emitted with incidence of the measurement-object light to the photodetector, and thereby obtains the intensity of the measurement-object light.

Light measuring apparatus for quantifying photons

When incident light is incident to a photodetector, photoelectrons are emitted and multiplied in each of incident zones whereby a plurality of current signals are output. These current signals each are processed to estimate a distribution or a mean value of numbers of photoelectrons generated in each incident zone. Then estimated based on the estimate values of respective incident zones is the number of photoelectrons emitted from the entire photoelectric conversion surface. In this way the intensity of incident light is measured with accuracy.

Growing community of inventors

Hamakita, Japan

Hisayoshi Takamoto