1. By yonis Nuradin Prof. Heather Kundzicz Prof. Sarah Feinman Bridges 13, 2014

2.  Kenneth Campbell, PhD Professor of Biology -- Reproductive En docrinology  Areas of Expertise Reproductive Endocrinology  Degrees PhD, Biochemistry, University of Michigan Ann Arbor MS, Biochemistry, University of Michigan Ann Arbor  Work Experience 2005-2008 Associate Dean of Science and Mathematics, University of Massachusetts, Boston

3. Spectrophotometry  spectrophotometer is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.  Turned spectrophotometer on and allowed to warm up for at least 10 minutes.  Set the wavelength using the keypad. Open compartment, and place a cuvette containing your blank.  Close the sample compartment door and press the( 0 ABS/100% T) button to blank the spectrometer at your chosen wavelength. The display will read 0.000 A (or 100.0 T)

4.  Now is ready to make an absorbance measurement on the sample.  Fill the cuvette with the sample and Continue to make measurements at this wavelength without re-blanking the instrument  If need to change the wavelength then to re-blank the spectrophotometer at the new wavelength.  To determine the absorbance of unknown make standard curve graph from data recorded then, determine the concentration of Unknowns either by estimation or by linear regression.