Sputo-LR™ is a sputum liquefying reagent for sputum and other mucoid fluids that is useful for the isolation of pathogenic or saprophytic bacteria, fungi, yeast, and epithelial cells. Sputo-LR™ is a concentrated sterile solution of Cleland ’s Reagent (dithiothreitol, DTT) in phosphate buffer at pH 7.0 and is for processing samples from sputum for smears and culture.

Sputum or phlegm is the discharge that is expectorated from the respiratory system. It is a heterogeneous and viscous substance that differs in appearance (mucoid, purulent, mucopurulent and blood-streaked). Consequently, the various host components and organisms in the sputum are not evenly distributed which makes it difficult to process multiple, equivalent samples for research and cryopreservation.

Sputo-LR™ chemically digests sputum to decrease viscosity and create a homogenous suspension that allows each sample to be an equivalent representation of the original sputum specimen. This chemical digestion or sputum liquefaction is accomplished with DTT. The active component of DTT is a sulphydryl group, which reduces the mucoprotein cross-linking disulfide bonds. A small amount of DTT is added to the specimen, so it does not affect morphology, growth or fluorescent antibody staining of pathogens in sputum.