Table 3.1: Quantification of a purification protocol for a fictitious protein

Step

Total protein (mg)

Total activity (units)

Specific activity (units mg−1)

Yield (%)

Purification level

Homogenization

15,000

150,000

        10

100

        1

Salt fractionation

  4,600

138,000

        30

  92

        3

Ion-exchange chromatography

  1,278

115,500

        90

  77

        9

Gel-filtration chromatography

           68.8

  75,000

  1,100

  50

    110

Affinity chromatography

               1.75

  52,500

30,000

  35

3,000