Lecture 13 Lab Lingo Flashcards
Absorbance Spectrophotometry
Concentration of an unknown sample is determined by measuring its absorption of light at a particular wavelength and comparing the rest with that of a known standard solution measured at the same time, and with the same wavelength.
Absorbed
Taken in or soaked up.
Beer’s Law
The amount of light absorbed by a solution is directly proportional to the concentration of a solution (↑ concentration ↑ light absorbed)
Bioluminescence
Form of chemiluminescence found in biological system
Blank Solution (Blank)
Contains all of the reagents used in the procedure w/o the unknown substance
Chemiluminescence
Chemical Reaction that produces light without producing heat
Concentration
A measure of the amount of solute that has been dissolved in a given amount of solvent or solution.
Cuvette
Small vessel designed to hold a liquid sample in the light path of a spectrophotometer for measurement
Directly Proportional
Related so that one becomes larger or smaller when the other becomes larger or smaller.
Electrochemiluminescence
The process where species generated at electrodes undergo electron-transfer reactions to form excited states that emit light
Electromagnetic Radiation
A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously.
Fiberoptics
Used to improve directional control of the light beam within the instrument
Fluorescence
When a molecule absorbs light at one wavelength and reemits light at a longer wavelength
Fluorescence Spectrophotometry
Uses a beam of light, typically UV light, to excite electrons in molecules causing them to emit light of a different wavelength.
Fluorimetry
Measures the fluorescence at a specific emission wavelength after induction with a light pulse of a specific excitation wavelength.
Fluorometer
Measures fluorescent intensity. Mainly the same components as spectrophotometer with the exception of the light source, sample cell, and detector.
Fluorophore
An atom or molecule that fluoresces.
Frequently used as tags/labels in immunoassay and flow cytometry.
Frequency
Measured in hertz (Hz) which is equal to one event per second.
Inversely Proportional
When the value of one quantity increases with respect to decrease in other or vice-versa.
Light
Form of electromagnetic radiant energy that travels in waves.
Light Source
Incandescent lamps, hydrogen or deuterium lamps, lasers, etc.
Linearity
The property of a mathematical relationship that can be graphically represented as a straight line. Linearity is closely related to proportionality.
Luminometer
Measures light emission via chemiluminescence, bioluminescence, and electrochemiluminescence.
Monochromator
Isolates radiant energy of a desired wavelength(s) while excluding other unwanted wavelengths.
Nanometers
A nanometer is one billionth of a meter, or 10^-9 meters.
Nephelometry
Based on detection of the portion of light scattered by the particles in a solution toward a detector not in the direct path of the transmitted light.
Used to assay large particles at low concentrations.
Photodetector
Convert light into a measurable electrical signal by detecting photons that strike a photosensitive or photoemissive surface.
Photometry
Technique used to determine the concentration of a substance by measuring variation in its color intensity.
Plank’s Equation
Shows relationship between wavelength and energy.
Readout Device
Information from an automatic device (as a computer) that is recorded or presented in a form that can be seen.
Reflectance Density
The amount of light absorbed by the colored reaction product on the smooth surface.
Inversely proportional to the light intensity reflected by the sample.
Reflectance Spectrophotometry
Light reflected from the surface of a colorimetric reaction is used to measure the amount of unknown colored product (quantitative)
Spectrophotometry
The measurement of light at selected wavelengths, typically in ranges of ultraviolet (UV), visible, and infrared light.
Spectrum of Energy
Short wavelengths gamma rays; long wavelengths radio frequencies.
Visible: ~380 - 750 nm
UV: 10 - 400 nm
Color of light seen by the naked eye is transmitted (or reflected), all other wavelengths are absorbed.
Standard Curve
Absorbance (or %T) of known standards is obtained.
Absorbance and concentrations are plotted on linear graph paper; concentrations of unknowns can be obtained using the curve produced based on the absorbance measured.
Transmitted
Light being reflected off of a surface/sample; the color that we see.
Turbidimetry
Measures the reduction of light transmitted through a homogeneous solution due to light’s scattering (solution becomes turbid)
Used to assay small particles at high concentrations.
Visible Light
Wavelengths of light between 380 and 750 nm.
Red
Wavelength
The distance between two peaks as light travels in a wavelike manner.
