Table:
Allergen	Concentration of the allergen
SPT	BAT
Cat pelt	10,000 BAU/ml	100 BAU/ml
Dog epithelium	1:20	1:2000
Dermatophagoides pteronyssius (DP)	1000 AU/ml	100 AU/ml
Dermatophagoides farinae (DF)	1000 AU/ml	100 AU/ml
Alternaria	1:10	1:1000
Hormodendrum/Cladosporium	1:10	1:1000
Timothy grass pollen	100,000 AU/ml	1000 AU/ml [BAT]
Short ragweed pollen	1:20	1:2000
Birch tree (Betula verrucosa) pollen	1:20	1:2000

Transcribe the table into Markdown format.

| Allergen | <COLSPAN=2> Concentration of the allergen | 
 | --- | --- | --- | 
 |  | SPT | BAT | 
 | Cat pelt | 10,000 BAU/ml | 100 BAU/ml | 
 | Dog epithelium | 1:20 | 1:2000 | 
 | Dermatophagoides pteronyssius (DP) | 1000 AU/ml | 100 AU/ml | 
 | Dermatophagoides farinae (DF) | 1000 AU/ml | 100 AU/ml | 
 | Alternaria | 1:10 | 1:1000 | 
 | Hormodendrum/Cladosporium | 1:10 | 1:1000 | 
 | Timothy grass pollen | 100,000 AU/ml | 1000 AU/ml [BAT] | 
 | Short ragweed pollen | 1:20 | 1:2000 | 
 | Birch tree (Betula verrucosa) pollen | 1:20 | 1:2000 |