Preparation of 0.5% McFarland for microbiology laboratory use

1. Prepared by- Arpita Chandra

2.  1% H2SO4
 1% BaCl2
 DISTILLED WATER (DW)
Make solution of any concentration-
Formula-
C1V1= C2V2

3. USE formula
C1V1 = C2V2
5 x V1=1 x 10 ml
V2 = 2 ml
C1 = Concentration of solution we have
V1 = Quantity of solution we have to add
C2 = Concentration of solution we need
V2 = Total quantity of the prepared solution
So, for the preparation of
10ml 1% H2SO4 = 8 ml DW + 2ml 5% H2SO4

4. USE formula
C1V1 = C2V2
10 x V1=1 x 10 ml
V2 = 1 ml
C1 = Concentration of solution we have
V1 = Quantity of solution we have to add
C2 = Concentration of solution we need
V2 = Total quantity of the prepared solution
So, for the preparation of
10ml 1% BaCl2 = 9 ml DW + 1ml 10% BaCl2

5. Add 9.95ml 1% H2SO4 + 0.05 ml 1% BaCl2
0.5% Mcfarland prepared
Transfer it on a glass transparent seal tight
bottle…. Store it on cool…

6. Thank you