Line Probe Assay: A New Arrival at the PRL discusses a new diagnostic tool, the line probe assay, that has arrived at the Provincial Tuberculosis Reference Lab in Sindh, Pakistan. The line probe assay can simultaneously detect resistance to rifampicin and isoniazid in mycobacterium tuberculosis, with a sensitivity of over 90% and specificity of over 99% for smear-positive specimens. It provides results faster than conventional drug susceptibility testing methods like solid and liquid culture. The new diagnostic tool will help improve case detection and management of drug-resistant tuberculosis in Pakistan.