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.
The isoelectric point of casein is 4.6. Since milk's pH is 6.6, casein has a negative charge in milk. The purified protein is water-insoluble. While it is also insoluble in neutral salt solutions, it is readily dispersible in dilute alkalis and in salt solutions such as sodium oxalate and sodium acetate.asein contains a fairly high number of proline residues, which do not interact. There are also no disulfide bridges.