Perth Amboy evening news., 1923-09-08
STANDARDIZING BIOLOGICAL
STAINS IS DISCUSSED BY HASKIN

in any number of other ways, and
while dyes are not made by mixing
colors the possibilities of completely
are endless.
American Dyes Purer
The Bureau of Chemistry gather
ed up an array of samples from
Germany and America and found
that 1t could not distinguish chemi-
cally the ones that would stain bac-
terra from those that would not.
Generally the American dyes were
purer and stronger.
DIR. Amber tells of one dye which
the Americans made called methyl
green. This is made from violet by a
simple process, and the American
product was very pure, but so far as
biology went 1t was useless. One
organism reacted to the German
methyl green by turning a pale rose
color. Chemists happened to hear
of this particular reaction. and they
at once deduced that the Germans
must have left a little violet in the
green dye. This turned out to be
the case. When the last bit of vio-
let was carefully eliminated the rose
possibilities were lost.
1t was eventually pointed out that
the dyes sold by the German dealer
were bought up by him from the
German market. Years before, he
had bought all kinds of textile dyes
and tried them out as stains. The
successful ones he continued to
buy, in order to sell them to the
scientific world. The dyes, there
fore, were ordinary textile dyes,
which are rarely pure colors. Afiny
amount of some different color, in
visible to the eye, may be put In to
correct the shade. The Bureau chem
lists found that 1t was this bit of
color which was the important fac
tor in some other cases besides that
Of the methyl green.
DIR. Amber points out that the
manufacture of dyes has proceeded
, considerably faster than the means
of detecting the ingredients. In the
early days of textile dyes, the pro-
ucts were fairly simple. Now, DIVES
must be amazingly complex in or
der to Withstand sun rain, and per-
SEPARATION. Such compounds defy test
tube and microscope.
The Government chemistg- fell
back on the spectroscope to detect
the color elements in the stains. A
spectroscope is an instrument in
which a prismatic band of colors is
the chief feature. When a light is
thrown on the prism and a solution
of a dye is placed between the light
and the prism, the dye shuts out GER
tain colors, generally those which
are complementary to the colors
shown in the dye itself.
Besides working with the spectro-
scope, the color chemists are study
ng the properties of dye informed
ates for the American dye industry,
and are also trying to evolve stand
ards for the biological stains. The
Government is not making any of
these stains for the market. They
are made by manufacturers, and the
Commission for Standardization of
Biological Stains, of which DR.. Am
bier Is a member, examines samples
sent to it and approves those that
pass a double test.
The aim is to establish standards
nd with the manufacturers COOPER
alton to label standard stains. So
Tar one dye has been certified as
standardized goods. This is methv-
lene blue, one of the most used stains
Tor diphtheria and various common
bacteria. AS there are from $50 10
2OO stains in scientific use, II can he
cen that the work of s~tandardiza.
ion by the government has lust he.
gun.