Gram-positive bacteria show blue or purple after Gram-staining in a laboratory test. They have thick cell walls. Gram-negative bacteria show pink or red on staining and have thin walls.

Your doctor may use an acid-fast bacteria (AFB) stain test to see if you have a lung disease like tuberculosis (TB). In addition to showing tuberculosis, an AFB stain can also show if you have ...

A team of researchers at the University of California, Los Angeles (UCLA) has introduced a virtual Gram staining technique that could transform how microbiologists stain and classify bacteria.

If your doctor suspects you have an infection, they may order a culture and gram stain to check for bacteria. If bacteria are present, this test can also help your doctor learn if the bacteria are ...

Gram staining is one way scientists can identify bacteria. Gram-positive bacteria, such as Staphylococcus, appear blue or purple under a microscope when scientists apply a stain. Conversely ...

Your doctor can order this test to find out if you have tuberculosis (TB) or another type of bacterial infection. TB was very common at one time. However, it’s now rare in the United States.

With delicate hues of purple and pink, a lab technique called gram staining has reliably characterized bacteria for more than a century. Yet many scientists are mistaken about why the vivid method ...