This test method describes a procedure for determining the electrophoretic mobility of proteins of molecular weight greater than 10 000 Daltons.

Formerly under the jurisdiction of Committee E55 on Manufacture of Pharmaceutical Products, this guide was withdrawn in August 2014. This standard was withdrawn without replacement due to its limited use by the industry.

The prime purpose of this test method is to provide data expressed as either electrophoretic mobility or zeta potential distribution of protein particles.

Both sellers and purchasers of protein particles will find this test method useful to determine either mobility or zeta potential distributions for protein specifications, manufacturing control, and development and research.

1.1 This test method describes a procedure for determining the electrophoretic mobility of proteins of molecular weight greater than 10 000 Daltons.

1.2 This test method uses automatic Electrophoretic Light Scattering (ELS) principles to determine the electrophoretic mobility.

1.3 The instrument simultaneously measures the Doppler shifts of scattered light at four different angles to determine the electrophoretic mobility distribution of protein particles. The mobility is expressed as m-cm/V-s (micron-centimeter/volt-second).

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.