But things get much murkier when it is a task order for a defense customer issued against a civilian IDIQ. There are about a dozen protests pending at GAO right now that fall into that crossover category, where a defense agency used a GSA contract such as Alliant or OASIS to hire a contractor.
purified protein derivative (PPD). [pyoÌoÌâ²rifÄ«d]. a dried form of tuberculin used in testing for past or present infection with tubercle bacilli. This product is usually introduced into the skin during such tests and may produce a tuberculin reaction (wheal) within 48 to 72 hours.
Tuberculin is a glycerol extract of the tubercle bacillus. Purified protein derivative (PPD) tuberculin is a precipitate of species-nonspecific molecules obtained from filtrates of sterilized, concentrated cultures. The tuberculin reaction was first described by Robert Koch in 1890.