SDS PAGE sample prep - (Mar/03/2014 )

Hello:

I need help figuring out the calculations for this sample prep:

Prepare samples to a final conc. of 0.2 micrograms/microliter with sample buffer (25% v/v), reducing agent (10% v/v) and water. For samples of different conc. adjust the dilutions proportionally.

Nominal sample conc.               sample                sample buffer          reducing agent        water

(% w/w)                                       (ul)                           (ul)                           (ul)                      (ul)

0.3                                                 2                            7.5                             3                       17.5

0.2                                                 3                             7.5                            3                       16.5

0.1                                                 6                             7.5                             3                       19.5

My samples are in liquid.

So what are the concentrations of your samples.... the table I see here doesn't seem to have any obvious problems.

The sample concentrations are in the first column, as (% w/w).

How can you start with a 0.2% w/w solution, add 3ul of this to the

total volume of 30ul, and end up with 0.2ug/ul ? I'm confused!

0.2% would be 2 mg/ml ((2/1000) *100) or 2 ug/ul, diluted 1:10 (or 3 in 30) would give you 0.2 ug/ul.