Bacteriology

Negative staining method permits visualization of the usually transparent and unstainable capsule of many organisms, most importantly Cryptococcus neoformans. Nigrosin consists of a suspension of fine particles of carbon. These form a dark background.

For the cultural isolation of Neisseria and Haemophilus species from a variety of clinical specimens.

For selective isolation and presumptive identification of group B Streptococci.

Recommended for selective isolation of Group B Streptococci from clinical samples.

Recommended for the selective isolation of Clostridium difficile.

Recommended for selective isolation of Pseudomonas aeruginosa from clinical specimens.

Recommended for selective isolation of Streptococcus species.

Recommended for detection of deoxyribonuclease activity.

Recommended for the selective isolation of Neisseria gonorrhoeae and Neisseria meningitidis.

Blood Agar Base w/ Nalidixic Acid is recommended for differentiation of haemolytic activity of Streptococci.It is a highly nutritive medium. Microorganisms producing haemolysin give visible haemolytic zones on this medium. Blood Agar Base is modified with addition of Nalidixic acid which acts as an inhibitor for the accompanying flora and to support the growth of Staphylococci, haemolytic Streptococci and Enterococci when supplemented with 5% blood. Nalidixic acid blocks the DNA replication of susceptible bacteria and acts against many Gram-negative bacteria.

Clostridium Difficile Agar Base is recommended for selective isolation of Clostridium difficile from food and certain pathological specimens.