# User:Elizabeth Ghias/Notebook/Experimental Biological Chemistry/2012/04/04

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## Objective

To determine the number of lysine residues that bound to the dye molecules.

## Description

1. Determine the concentration of a known dye solution.

The dye in solution has been prepared on the 21/2 using: m = 1mg of dye 5ml of water + 80µL of DMSO => Total volume = V = 0.0058L

MW of the dye = 573.51 g/mol

So, n = 10^-3/573.51 = 1.74* 10^-6 moles

And, C = (1.74* 10^-6)/0.0058 = 3*10^-4 M

2. Determine the molar absorptivity of the dye at 602 nm using a dye solution with a known concentration by using Beer's Law.

Molar absorbtivities (ε, L/mol/cm) were determined using Beer's law: A = ε*l*C

With A = absorbance at 602nm l = width of the cuvette (1cm) C = dye concentration (3*10^-4 M)

The molar absorptivity of our dye at 602nm is equal to = 3419 L.mol^-1.cm^-1 (It's determined by doing the average of the three different ε values)

3. Determine the molar absoptivity of the dye at 625 nm using a dye solution with a known concentration by using Beer's Law

Molar absorbtivities (ε, L/mol/cm) were determined using Beer's law: A = ε*l*C

With A = absorbance at 625nm l = width of the cuvette (1cm) C = 3*10^-4 M

The molar absorptivity of our dye at 625nm is equal to = 2204 L.mol^-1.cm^-1 (It's determined by doing the average of the three different ε values)

4. Determine the dye concentrations of the 70 molar ratio, 166 molar ratio and the BSA/HCl dye reactions

In this table are corrected value for Absorbance (Abs with dye - Abs without dye)

According to these data, we can calculate the dye concentration using Beer's law.

We know that: ε at 625nm = 2204 L.mol^-1.cm^-1

ε at 602nm = 3419 L.mol^-1.cm^-1

## Data

• Add data and results here...

## Notes

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