Microbiology laboratoric test

Gram Stain• Material

– solutions of crystal violet, Gram’s iodine (2 g potassium iodide in 300 ml distilled water plus 1 g iodine crystals), 95% ethanol and/or

– isopropanol-acetone mixture (3:1 v/v), and

– safranin– Bismark brown stain (for color-

blind students)– clean glass slides– inoculating loop– Bunsen burner– bibulous paper

– microscope– lens paper and lens cleaner– immersion oil– Hyphomonas (Hyphomicrobium)

neptunium (ATCC 15444) grown in marine broth (Difco)

– slide warmer– staining rack– Bacto Gram Stain Reagents from

Difco for the three-step Gram stain

Gram Stain

Gram Stain

Gram Stain

Gram Stain

Gram Stain

Gram Stain

Gram Stain

Gram Stain

Gram Stain

Gram Stain

Examination the preparation under microscope ( x100) for confirmation

Microscopic result for Gram Stain