positive
A negative result for the spores stain indicate that the gram-negative organism is present. A positive result for a spore stain indicates that a gram positive organism is present.
gram positive Exactly. When doing a gram stain on B. subtilis, this bacterium resists decolorization (keping the first stain and NOT taking on the color of the secondary stain). Therefore, this bacterium is gram (+).
Red or pink. Gram Positive = Purple or Violet, Gram Negative = Red or Pink. I just think of the mnemonic Positive-Purple both starting with P.
S. epidermidis is a Gram-positive bacterium. It appears purple when subjected to a Gram stain due to its thick peptidoglycan layer in the cell wall.
If the Gram Stain is completed properly, gram positive should stain purple; however, if you over decolorize a gram positive organism, the organism will appear appear pink, which is a gram negative reaction. To summarize, if you over decolorize a gram positive organism it will show as a gram negative organism.
The answer to whether HIV gram-stain positive or negative is that HIV gram-stain is negative. They retain the light red or pink color after the stain.
Gram positive
Contamination
Gram-positive bacteria which take up the stain turn purple, while Gram-negative bacteria which do not take up the stain turn red.
If iodine is not applied, both the gram-positive and gram-negative stains will appear to be gram-negative. The iodine acts as a mordant that helps to fix the crystal violet stain in the gram-positive bacteria, making them appear purple. Without iodine, the crystal violet stain can be easily washed out of both gram-positive and gram-negative bacteria, resulting in a pink or red color.
A negative result for the spores stain indicate that the gram-negative organism is present. A positive result for a spore stain indicates that a gram positive organism is present.
Gram-negative on a Serratia marcescens gram stain means that the bacterium has a cell wall that does not retain the crystal violet stain used in the gram staining procedure. This indicates that Serratia marcescens has a thin peptidoglycan cell wall, and the outer membrane contains lipopolysaccharides.
Bacteria stain either gram-positive or gram-negative based on the presence or absence of a cell wall. Viruses do not pick up a gram stain.
When a gram stain is done on Shigella flexneri, the cells are light pink. This means that they are gram negative.
Measles virus is a negative-sense, single-stranded RNA virus and does not have a cell wall structure that can be stained with the Gram stain. Instead, measles virus particles can be visualized using specialized staining techniques such as immunofluorescence or electron microscopy.
gram positive Exactly. When doing a gram stain on B. subtilis, this bacterium resists decolorization (keping the first stain and NOT taking on the color of the secondary stain). Therefore, this bacterium is gram (+).
Gram Negative