APPLICATION NOTE

Assessing Proteins Across Grades and Suppliers.

Selecting the optimal supplier and the optimal grade of a protein for study or further synthesis is a challenging task for the end user.

 If the supplier or manufacturer’s characterization provides inadequate information or detail compared with what the end user needs to know, the task falls to the QC/QA department to provide the missing data.

 The two chromatograms below illustrate degrees of variation typically found across grades of protein from the same supplier. Each chromatogram shows two grades of ovine albumin from each vendor:

Note: To minimize the amount of test protein required and the waste generated, this analysis is performed with a narrow bore STYROSä HQ/NB column. Table 1 shows the operating parameters.

Table 1. Operating Parameters.

	HPLC System	HP 1100
	Detector	280 nm
	Column	STYROS™ HQ/NB 150 x 2.1mm
	Mobile Phase	A: 20 mM Tris, pH=8.2 B: A + 1 M NaCl
	Gradient	7 to 30 % B in 18 Column Volume
	Flow rate	0.5 ml/min (870 cm/hr)
	Temperature	30 °C
	Injection volume	2 µl
	Sample:	OVA (5 mg/ml), Egg White (chicken)

A fresh dilution of egg white (1 to 9 in Buffer A) run on
STYROSä HQ/NB under similar conditions appears below:

Ovine albumin, the major component, is well separated from the complex mix by STYROSä HQ/NB.

The potential utility of such an approach for assessing available grades and suppliers should be self-evident.

The analysis addresses and clearly answers the specific questions of potential end users.

STYROSä HQ/NB tolerates pressures up to 5,000 psi allowing high flow rates for both rapid sample analysis and efficient column re-equilibration.

The high capacity or STYROSä HQ/NB’s quaternary amine surface and its fully pervious structure provide rapid and sensitive resolution of complex mixes.

 

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