Microbiology

MacConkey Agar without Salt

Recommended as a differential medium for the selection and recovery of the Enterobacteriaceae and related enteric gram-negative bacilli.

Range	Microbiology
Composition	Concentration (g/l): Peptone 1.5; Tryptone 1.5; Gelatin peptone 17; Lactose 10; Bile salts 1.5; Crystal violet 0.001; Neutral red 0.03; Agar 15; Final pH 7.1 ± 0.2 at 25°C.
Preparation	Suspend 18 grams in 950 ml purified / distilled water. Adjust pH to 6.8 ± 0.2 at 25°C. Heat if necessary to dissolve the medium completely. Dispense in 95 ml amounts into flasks and sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to about 50-55°C and add aseptically 5 ml sterile 40% Urea solution per 95 ml basal medium. Mix well and dispense into sterile test tubes. Allow to cool in an upright position. Do not overheat or reheat the medium as urea decomposes very easily.
Storage	Lab.Vie. MacConkey Agar without salt should be stored between 10-30°C in a firmly closed container and the prepared medium at 2-8°C. Use before expiry date on the label. On opening, product should be properly stored dry, after tightly capping the bottle in order to avoid lump development due to the hygroscopic nature of the product. Improper storage of the product may lead to lump formation. Store in a dry ventilated area protected from extremes of temperature and sources of ignition. Seal the container tightly after use. Product performance is best if used within stated expiry period.
Appearance	Lab.Vie. MacConkey Agar without salt is Light yellow to light pink homogeneous free flowing powder. Prepared medium is Orange red coloured clear to slightly opalescent gel forms in Petri plates. If there are any physical changes, discard the medium. Media should not be used if there are any signs of deterioration (shrinking, cracking, or discoloration), and contaminations.
Specimen	For clinical samples follow appropriate techniques for handling specimens as per established guidelines (7,8). For food and dairy samples, follow appropriate techniques for sample collection and processing as per guidelines (3,9). For water samples, follow appropriate techniques for sample collection, processing as per guidelines and local standards (4). After use, contaminated materials must be sterilized by autoclaving before discarding. Type of specimen: Clinical - faeces, urine, Foodstuffs and Dairy samples, Water samples
Pack sizes	3 options