Gram stain reagents

These stains can be ordered as a complete kit from VWR (#l5204-004) or can be reconstituted as follows:

Crystal violet

crystal violet (90% dye content) 20.0 g

ethanol (95%) 200 mL

ammonium oxalate 8.0 g

dH₂0 800 mL

Mix first two ingredients and let sit overnight or until dye goes into solution. Add remaining ingredients and filter before use.

Gram's iodine

iodine crystals 1.0 g

potassium iodide 2.0 g

dH₂0 300 mL

Decolorizer

acetone 40 mL

ethanol (95%) 60 mL

Safranin

safranin O 2.5 g

95% ethanol 100 mL

dH₂0 900 mL

Filter safranin solution before use.

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