SUPPLEMENT TO EMPLOYMENT AGREEMENT dated June 22, 1999 by and between QIAGEN GmbH, Max-Volmer-Str. 4, 40724 Hilden - hereinafter QIAGEN - and Dr. Joachim Schorr - hereinafter Employee -

Exhibit 4.22

SUPPLEMENT TO EMPLOYMENT AGREEMENT

dated June 22, 1999

by and between

QIAGEN GmbH,

Xxx-Xxxxxx-Xxx. 0, 00000 Xxxxxx

- hereinafter QIAGEN -

and

Xx. Xxxxxxx Xxxxxx

- hereinafter Employee -

The following supplement has been added to the Employment Agreement dated June 22, 1999.

Article 5

Salary

(5) The Employee will be provided with a business vehicle which he may also use for private use without restriction. Excluded is foreign travel for which the Employee bears the expenses. The monetary value of private vehicle use subject to income tax in conformity with tax regulations and chargeable to the Employee is taken into account in the payment of remuneration indicated in Article 5.1.

Hilden, June 23, 1999
QIAGEN GmbH				Employee
		In representation of
/s/ XX. XXXXX XXXXXX		Xxxxxxx Xxxxxx		/s/ XX. XXXXXXX XXXXXX
Xx. Xxxxx Xxxxxx		Xxxxxxx Xxxxxx		Xx. Xxxxxxx Xxxxxx