Help with preparing Congo Red TSA
1) Yes, that's correct.

2) This is just a simple matter of applying the equation $C_1V_1=C_2V_2$. For congo red:


$C_1=20\frac{mg}{mL}$
$C_2=0.04\frac{mg}{mL}$
$V_2=500\ mL$


I'm sure you and a calculator can figure the rest out.