Blood Agar (BA)

Transport medium helps preserve bacteria that are difficult to grow, such as Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria species
Code: 08021
Packaging: 50 tubes/ box or as per customer request.
Storage Conditions: 2–8°C.
Transportation: Ambient temperature.
Shelf Life: 6 months from the date of manufacture.

INTENDED USE

BacterTube™ Blood Agar (BA) is primarily used for preserving and transporting bacteria under warm environmental conditions. This medium helps maintain the viability of bacteria for a short period and ensures the survival of hard-to-culture bacteria such as Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria spp. and other bacterial strains that require blood-derived nutrients. Using this medium in slant tubes provides a larger surface area for bacterial growth and facilitates convenient transportation of samples without compromising their quality.

PRINCIPLES

Peptones included in the composition of the medium favor the excellent growth of colonies.
Yeast extract is a source of vitamin B complex.
Starch is a detoxifying agent and also an energy source.
Defibrinated sheep blood provides X factor (heme), essential for the growth of many fastidious bacteria, and allows the detection of hemolytic reactions.

Heat the loop’s tip until it becomes red in the flame, then lightly heat the handle of the loop, ensuring the loop is uniformly hot.
Inoculate the medium by gently placing the loop’s tip on the surface of the slant agar at the bottom of the tube.
Next, streak in a zigzag pattern from the bottom of the tube to the top along the surface of the slant..
Place the tube in the incubator under aerobic conditions at 35 – 37°C for 18 – 24 hours.

RESULTS

Observe the bacterial growth.

Beta hemolysis
- Streptococci belonging to Lancefield group A appear as small, grey colonies, translucid or opaque, surrounded by a zone of beta hemolysis. Other bacteria may present the same type of hemolysis: Listeria, hemolytic Staphylococci, Escherichia coli and Pseudomonas.
- Staphylococci appear as opaque, yellow-gold or white colonies, with or without type β hemolysis zones.
- Listeria present small zones of beta hemolysis.
- Bacillus cereus form a clear zone surrounding the colonies.
Alpha hemolysis
- Pneumococci appear as flat, shiny, grey and occasionally mucoid colonies surrounded by a zone of narrow, greenish hemolysis referred to as alpha hemolysis.
CAMP Factor
- Group B Streptococci produce an extracellular, thermoresistant substance (CAMP Factor) which provokes a triangle of total hemolysis in a zone of incomplete staphylococcal hemolysis, at the junction of the two cultures.

BacterLab ensures the quality of each product batch by testing with ATCC reference strains.

Reference strains	Incubation Conditions	Standard (P_R)
S. pneumonia ATCC 49619	Incubate for 24 – 48 hours, at 35 – 37°C, with inoculum ≤ 10³ – 10⁴ CFU/ mL	Good growth, α hemolysis
S. pyogenes ATCC 19615		Good growth, hemolysis
E. faecalis ATCC 29212		Good growth, ɤ hemolysis