EPA Science Inventory

ENHANCED DAPI STAINING FOR CRYPTOSPORIDIUM IN WATER SAMPLES

Citation:

Ware, M. W., F. W. Schaefer III, AND H. A. Lindquist. ENHANCED DAPI STAINING FOR CRYPTOSPORIDIUM IN WATER SAMPLES. Presented at American Society for Parasitologists Annual Meeting, Albuquerque, NM, June 29-July 3, 2001.

Description:

The U.S. Environmental Protection Agency's Method 1623 is used to detect and quantify the presence of {ital Cryptosporidium} spp. oocysts in water. The protocol consists of concentrating a sample, staining this concentrate with a fluorescent antibody, and examining the sample microscopically. Since algae can be misinterpreted as positives using this procedure, confirmation may be done by either differential interference contrast microscopy, or by observation of the staining pattern when stained with 4,6-diamidino 2-phenyl-indole dihydrochloride (DAPI). Our research has shown that differential interference contrast is only able to confirm about 2% of oocysts with sporozoites in a fresh preparation. The rate of confirmation is improved to around 30% with DAPI staining when following the Method 1623 protocol. By a slight modification of the DAPI protocol, the confirmation rate improves to nearly 100%. A number of formats for optimizing slide preparation have been tested. Confirmation by both fluorescent antibody and DAPI staining is also possible using flow cytometry.

Purpose/Objective:

1) Refine new, practical methods for the detection of CCL-related and emerging waterborne human protozoa.

2) Perform field tests of devices or methods that have been developed under this task.

3) Evaluate these methods or devices in a variety of water matrices and parasite concentrations.

This work in this task supports CCL2 and 3 and is expected to be completed by 9/07.

Record Details:

Record Type: DOCUMENT (PRESENTATION/ABSTRACT)
Start Date: 06/29/2001
Completion Date: 06/29/2001
Record Last Revised: 06/21/2006
Record Created: 09/26/2003
Record Released: 09/26/2003
Record ID: 61031

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL EXPOSURE RESEARCH LAB

MICROBIOLOGICAL AND CHEMICAL EXPOSURE ASSESSMENT DIVISION

BIOHAZARD ASSESSMENT RESEARCH BRANCH