Zipf's Law Microarray Normalization




Introduction

This page accompanies our published description of a microarray normalization method using Zipf's Law. A detailed description of the method can be found in the original paper:

       Can Zipf's law be adapted to normalize microarrays?
       Lu T, Costello CM, Croucher PJP, Haesler R, Deusch G, Schreiber S.
       BMC Bioinformatics 2005, 6:37

       Pubmed ID: 15727680


Sample data sets

Two data sets were described in the original article. These text files are tab delimited and in the following format:


Norm_CD_UC_data.txt
  • Microarray type: Filter based cDNA from the RZPD
  • Number of genes: 33,792
  • Number of microarrays: 31
  • Probed with: Total RNA from human sigmoidal colon.
  • Within microarray normalization: None
rat_raw.txt
  • Microarray type: Clonetech Atlas Rat cDNA 7738-1
  • Number of genes: 558
  • Number of microarrays: 33
  • Probed with: Total RND from rat cerebellum and olive.
  • Within microarray normalization: None
Mouse_raw.dat
  • Microarray type: Custom two-channel boutique microarray
  • Number of genes: 447
  • Number of microarrays: 5 (2 channels each)
  • Probed with: Total RNA from mouse cell lines.
  • Within microarray normalization: None


Normalization software

Three implimentations of the Zipf's Law normalization have been developed, two are available for download.

ZipfsNormalize.xls Excel Macro

Requires: Microsoft Excel
(Does not handle missing data values.)
Installation Instructions

zipfs_normalize.pl Perl Script

Requires: Perl (which runs on many platforms), the PDL perl module
(Handles missing data values if PDL is compiled correctly.)
Installation Instructions




Last updated: 07.03.2005