Title:
【発明の名称】標識した微生物宿主細胞株を使用するアッセイ
Document Type and Number:
Japanese Patent JP2001502917
Kind Code:
A
Abstract:
Presence of a contaminating microbial host cell (A), in a culture vessel containing a different host cell (B) able to use more than one carbohydrate (I), is detected by: (a) culturing (B), which includes nucleic acid encoding a particular polypeptide (II) and genetically marked so that it can not use a selected (I), (Ia), as substrate; (b) plating an isolated sample of the culture on a medium supplemented by (Ia); (c) incubating the plated cells, and (d) detecting if any colonies grow in the (Ia)-containing medium. Optionally (A) that grow in the supplemented medium may be plated on a field of different (I) to identify them from their specific (I)-utilising characteristics. The cells are yeasts or prokaryotes, particularly Gram-negative bacteria and specifically E. coli. They express an exogenous (II) and utilise e.g. maltose, ribose or rhamnose. (B) is genetically marked by making (a) a non-reversing, non-suppressing alteration in its genotype, in which case the sample is not diluted before plating or (b) a genotypic alteration that results in a carbohydrate utilisation revertant or suppressant, in which case the sample is serially diluted before plating. Optionally the strain is doubly marked by altering two (I)-utilisation pathways; (i) one type (a), in ribose utilisation and the other a reverting or suppressing mutation in rhamnose utilisation or (ii) both type (a), in maltose and ribose utilisation. Where two alterations are present, two plates are used in step (b), each supplemented with different (I). The vessel is a fermentor containing, before dilution, 108-1011 colony-forming units (cfu)/ml.
Inventors:
McFarland, Nancy See.
Swartz, James Earl.
Swartz, James Earl.
Application Number:
JP52067698A
Publication Date:
March 06, 2001
Filing Date:
October 10, 1997
Export Citation:
Assignee:
Genentech, Inc.
International Classes:
C12Q1/02; C07K14/00; C12N1/21; C12P21/00; C12Q1/04; C12Q1/06; C12R1/19; (IPC1-7): C12Q1/02; C07K14/00; C12P21/00
Attorney, Agent or Firm:
Shusaku Yamamoto