BCA Protein Assay

[Shaun D. Black]

Guy-
     Take a look at Christia Stoscheck's article in Methods Enzymol 1=
82:
50-68 (1990).  It contains a wealth of practical information on UV, C=
opper,
Coomassie, BCA, and colloidal Gold protein assays.  It is easy to fol=
low=20
her protocols for each assay.  The BCA assay begins on p.60, as follo=
ws:

     Reagent A: 1g    Sodium bicinchoninate (BCA)
                2g    Sodium Carbonate
                0.16g Sodium tartrate
                0.4g  Sodium hydroxide
                Bring to 100 ml volume with water
                Adjust pH to 11.25 with 10 M NaOH

     Reagent B: 0.4g  Copper sulfate (pentahydrate)
                Bring to 10 ml with water

     Standard Working Reagent (SWR): Mix 100 vol of Reagent A with 2 =
vol B
                SWR should be stable for 1 week and should be green.

Combine 1ml SWR and 20 uL of sample; mix.
Incubate 30 min at 60=B0C.
Read Absorbance at 562nm; readings stable for about 1 hr.

There is also a recipe given for a BCA micromethod, on p. 61.  Hope t=
his=20
helps.  Cheers,  Shaun
  ==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-=
==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-===20
  == Shaun D. Black, PhD     | Internet:  shaun%jason.decnet at relay.th=
e.net ===20
  == Dept. of Biochemistry   | University of Texas Health Center, at =
Tyler ===20
  ==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-=
==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-===20