Please enable JavaScript.
Coggle requires JavaScript to display documents.
biochemical test iMVic test - Coggle Diagram
biochemical test iMVic test
INDOLE TEST
PRINCIPLE: Tryptophan is converted into
indole+pyruvic acid +ammonia by
tryptophanase
MEDIA:Peptone broth ,SIM agar medium,tryptophan broth
REAGENT: Kovac's reagent
COMPOSITION:Para- dimethylaminobenzaldehyde -react with indole to form red resindole dye
Butanol:help to draw indole to surface
Hcl:Cataylst,degrade p-dimethylaminobenzaldehyde
RESULT:POSITIVE- PINK TO CHEERY RED RING FORMATION
NEGATIVE- YELLOW COLOUR
Dehydration ,reduction
METHYL RED
MIXED ACID FERMENTATION- PRINCIPLE: Glucose +H2O gives- acids+Co2+H2 pH =4.0
MEDIA: MR-VP broth
REAGENT: Methyl red indicator for acidic end product identification
RESULT:POSITIVE - RED COLOUR pH=BELOW 4.4 NEGATIVE - YELLOW COLOUR pH =ABOVE 5
VOGES-PROSKAUER TEST
ALKALINE END PRODUCT -PRINCIPLE: Glucose +O2 gives acetic acids -1.acetoin 2.acetylmethyl carbinol 3.2,3-butanediol +Co2 +H2 pH=6.0
MEDIA : MR -VP broth( BUTANEDIOL - FERMENTATION PATHWAY)
REAGENT :Barritt's A-Alpha napthol colour intensifier and react with diacetyl to form colour complex ,catalyst
Barritt's B- KoH Oxidizing agent 40 %
RESULT: POSITIVE -PINK TO RED COLOUR CHANGE NEGATIVE -REMAINS IN YELLOW COLOUR
CITRATE UTILIZATION TEST
Sodium citrate gives oxaloacetate + acetate Oxalocetate gives pyruvate +C02
C02+Na+H2O gives Na2Co3 alkaline pH colour change
MEDIA:simmon citrate agar medium
REAGENT \INDICATOR :Dipotassium phosphate -buffering agent Bromothymol blue -changes from green to prussian blue
Magnesium sulfate - provide essential ions
sodium chloride -maintain osmotic balance
RESULT: POSITIVE -PRESENCE OF GROWTH ON SURFACE OF SLANT -blue colorization
NEGATIVE - ABSENCE OF GROWTH ON SURFACE OF SLANT - green colorization