X-Factor Discs are used for the presumptive identification of Haemophilus species based on their requirements for X or V growth factors or both. Members of the genus Haemophilus require accessory growth factors for in vitro growth. Some Haemophilus spp. require X factor (hemin) alone, V factor (nicotinamide adenine dinucleotide [NAD]) alone, or a combination of both. Consequently, this significant difference in growth factor requirements of Haemophilus spp. allows for their differentiation. X factor comprises protoporphyrin IX, also called hemin or other iron-containing porphyrins. These are required for growth because X-dependent strains cannot convert d-aminolaevulinic acid to protoporphyrin. The organisms will grow only around the disk that provides the appropriate factor for their growth. Hence, differentiation is based on the presence or absence of growth around the discs impregnated with X-factor.
應用
X-Factor Discs are used for the presumptive identification of Haemophilus species and find their application in various sectors such as the food and dairy industry, water industry, pharmaceutical laboratory testing, cosmetic industry, environmental and sanitary testing, clinical diagnostic, etc.
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