Appendix

APPENDIX 2F Testing Hygrometers Used in Cytogenetics Laboratories for Metaphase Preparation

  1. Thomas Hartley1,
  2. Karen Dun2

Published Online: 1 JUL 2011

DOI: 10.1002/0471142905.hga02fs70

Current Protocols in Human Genetics

Current Protocols in Human Genetics

How to Cite

Hartley, T. and Dun, K. 2011. Testing Hygrometers Used in Cytogenetics Laboratories for Metaphase Preparation. Current Protocols in Human Genetics. 70:2F:A.2F.1–A.2F.8.

Author Information

  1. 1

    Pathology Services, Royal Hobart Hospital, Hobart, Tasmania, Australia

  2. 2

    Cytogenetics Laboratory, Pathology Services, Royal Hobart Hospital, Hobart, Tasmania, Australia

Publication History

  1. Published Online: 1 JUL 2011
  2. Published Print: JUL 2011

Abstract

This protocol describes procedures for checking small laboratory hygrometers for accuracy at three relative humidity (rh) levels. The work arose out of the need to provide laboratory assessors with documentary evidence that the hygrometer used to monitor humidity in the vicinity of the laboratory where medical cytogenetics testing slides are prepared and dried in the ambient environment is reproducible and sufficiently accurate. The procedure is based upon the physicochemical principle that when water or certain saturated salt solutions are placed into a sealed environment, the humidity will equilibrate to well defined levels. We choose to check our hygrometers at three points: 95%, 75%, and 33% rh, using distilled water, saturated sodium chloride solution, and saturated magnesium chloride solution, respectively. Our results have demonstrated that the procedure is convenient and of sufficient accuracy to be fit for this annual hygrometer validation purpose. The procedure takes 24 hr per relative humidity point checked. Curr. Protoc. Hum. Genet. 70:A.2F.1-A.2F.8 © 2011 by John Wiley & Sons, Inc.

Keywords:

  • Hygrometer check;
  • ISO 15189;
  • slide drying;
  • environmental humidity;
  • chromosome spreading;
  • chromosome crossovers