Try perhaps also fluorescence microscopy with Calcofluor :

Cotton fibres contain mainly cellulose. The cellulose of plant cell 
walls can be stained with Calcofluor White (Fluorescence microscopy). 
But I never tried to stain cotton fibres with it...

You will find some informations about calcofluor (and also cotton 
fibres) at : http://www.dalynn.com/03access/sc15.html

Hope it helps !

Chris


>Cotton fibres also show strong birefringence using polarised light.
>                                         Regards,
>                                                     Tony
>Histopathology Group
>Asthma Biology Department.
>RIRP CEDD.
>GlaxoSmithKline Medicines Research Centre,
>Gunnelswood Road,
>STEVENAGE,
>Hertfordshire.
>   SG1 2NY
>tel.          +44 (0)1438 764117
>fax.         +44 (0)1438 764782
>email.    Tony.J.Savage@gsk.com
>mobile    +44 07753609835
>
>
>
>
>
>CrochiereSteve@aol.com
>
>16-May-2003 03:49
>
>
>
>
>         To:     histonet
>
>         cc:
>         Subject:        Staining of cotton in tissue
>
>We have an interesting autopsy case that demonstrates foreign body emboli
>in the lung tissue. The foreign bodies resemble cotton fibers. Does anyone
>know of a special stain that demonstrates cotton fibers? They stain with
>Congo Red and I have heard that they are acid fast positive. Is this true?
>Any suggestions are welcome.
>Thanks,
>
>Steven M. Crochiere, HT (ASCP)
>Histology Supervisor
>LifePath Partners @ Mercy Medical Center
>299 Carew St.
>Springfield, MA 01104


-- 
Christian Wuethrich, PhD
Harvard Medical School
Division of Viral Pathogenesis
Beth Israel Deaconess Medical Center
330 Brookline Avenue
Boston, MA 02215
United States