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السبت، 27 أكتوبر 2012

A book about the biological laboratory fourth penalty

A book about the biological laboratory fourth penalty
 
 

References

1.  MacFaddin JF, Bioche mical Tests for Identification of Medical Bacter ia, 2nd ed., Williams
and Wilkins, Baltimore MD., 1980, p51-58.

2.  Murray PA, et al.  Manual of Clinical  Microbiology, 7th ed ., 1999; pp 426-427.

PROCEDURE MANUAL
TORONTO MEDICAL LABORATORIES / MOUNT SINAI HOSPITAL MICROBIOLOGY DEPARTMENT 

Page 41

TML/MSH Microbiology Department
Policy & Procedure Manual
Policy # MI\TECH\10\v01  Page 1 of  1
Section: Technical Manual  Subject Title: Cetrimide Pseudomonas
 Selective Agar
Issued by:  LABORATORY MANAGER   Original Date: July 31, 2000
Approved by: Laboratory Director

Revision Date: February 15, 2002

CETRIMIDE PSEUDOMONAS SELECTIVE AGAR

Principle

Cetrimide Selective Agar is used for the identification of Pseudomonas aeruginosa.   Cetrimide is a
compound that has germ icidal activity against most organisms except  Pseudomonas aeruginosa.
Also pigment production is enhanced on this media. 

Procedure

1.   Divide the plate into approximately 8 pie shaped divisions.
2.   Streak the test organism (pure culture) onto one of the pie  shaped divisions.
3.   Incubate at 35
0
C for 18 - 24 hours.

Interpretation

Pseudomonas aeruginosa will grow on this media  and will be pigmen ted a pale green to dark blue-green colour.  All other organisms will not grow or will be non-pigmented.

Quality Control

Test with positive and nega tive controls ea ch time the test is set up.

 Positive:  Pseudomonas aeruginosa    (ATCC 27853) 
 Negative: Escherichia coli   (ATCC 25922)   

Reference

1.  PML Technical Manual,  1990. 

PROCEDURE MANUAL
TORONTO MEDICAL LABORATORIES / MOUNT SINAI HOSPITAL MICROBIOLOGY DEPARTMENT 

Page 42

TML/MSH Microbiology Department
Policy & Procedure Manual
Policy # MI\TECH\11\v01  Page 1 of 6
Section: Technical Manual  Subject Title: Cryptococcal Antigen
Issued by:  LABORATORY MANAGER   Original Date: March 20, 2000
Approved by: Laboratory Director

Revision Date: July 26, 2000

CRYPTOCOCCAL ANTIGEN

Latex particles coated with anti-cryptococcal globulin (ACGR) reacts with cryptococcal
polysaccharide antigen (in CSF or serum) causing a visible agglutination.

I. Specimen Collection and Processing

  5 mL of blood is collected in  a serum separator tube and separated by centrifugation. The
serum is removed to a vial and refrigerated until te sting. Specimens  are stored a
 -70o
C after testing.

  Spinal fluid is collected in clean, sterile, cent rifuge tubes.  Specimens are stored refrigerated
after testing.
  Note:  Fungus culture sh ould also be set up.

II. Procedure

 Reagents

  Meridian CALAS (Cryptococcal Antigen Latex Agglutination System)
  1.  GBDA - Glycine buffe red diluent with albumin.
  2.  ACGR - Anti-cryptococcal globulin reagent.
  3.  NGR - Normal globulin reagent.
  4.  AGC - Antiglobulin contro l.  Rehydrate with 1.5 mL dH
2
O.
  5.  NC - Negative control.  Rehydrate with 2.5 mL dH
2
O and  inactivate the negative
at 56
o
C for 30 minutes .
  6.  CAC - Cryptococcal antigen control (Positive control).
  7.  Pronase - Rehydrate with 2.5 mL dH
2
O.

Note:  Ensure that all reconstituted vials are thoroughly dissolved before use

  All reagents are stored refri gerated.  Do not interchange reagents with a kit having a
different lot number.  Allow reag ents to warm to room temperature before use.  Mix gently
before use.

PROCEDURE MANUAL
TORONTO MEDICAL LABORATORIES / MOUNT SINAI HOSPITAL MICROBIOLOGY DEPARTMENT 

Page 43

TML/MSH Microbiology Department
Policy & Procedure Manual
Policy # MI\TECH\11\v01  Page 2 of  6
Section: Technical Manual  Subject Title: Cryptococcal Antigen 

 Other Materials
 Boiling water bath
 56o
C heating block
  1.0 x 0.1 mL pipettes
 Rotator
  Small serologic test tubes
  Test tube rack
 Marking pen
 Applicator sticks

  The following are provided by Meridian:
 Capillary pipettes
 Rubber bulb
 Ring slide

 Method

 Specimen preparation:

  1.  Store refrigerated if testing is not done immediately.

    (a)  Inactivate serum by mixing 500 µL of serum and 500 µL of pronase solution
in a 12 x 75 mm tube and incubate at 56
o
C for 15 minutes.  Further
inactivate in a boiling water bath for 5 minutes.   This constitutes a 1:2
dilution.

  (b) Centrifuge CSF at 3500 rpm for 15 mins.  Inactivate the supernatant in a
boiling water bath for 5 minutes.


PROCEDURE MANUAL
TORONTO MEDICAL LABORATORIES / MOUNT SINAI HOSPITAL MICROBIOLOGY DEPARTMENT 

Page 44

TML/MSH Microbiology Department
Policy & Procedure Manual
Policy # MI\TECH\11\v01  Page 3 of 6
Section: Technical Manual  Subject Title: Cryptococcal Antigen 

Performing the tests:

Note:  Controls must be run each time a patient specimen is tested.

  1.  Set up and label  the slide as follows:

 
         










  2.  Gently resuspend the la tex particles in the ACGR an d NGR reagents.  Rock each
reagent just prior to use.
    Place one drop of ACGR or NGR into the designated rings.

3.   Place 25  µL (one drop) of the cryptococcal  antigen control (CAC) into the
designated rings.  Repeat with the negativ e control (NC) and anti-globulin control
(AGC)

 4. Place 25 µL of specimen in the designated rings.

  5.  Using a separate applicator stick, mi x the contents of each ring thoroughly,
spreading the contents over the entire surface area.

N
G
R


A
C
G
R

 CAC   NC  AGC   TEST
 (POS   (NEG  (Anti-
 Control)  Control) globulin
      Control)

Not
Used

PROCEDURE MANUAL
TORONTO MEDICAL LABORATORIES / MOUNT SINAI HOSPITAL MICROBIOLOGY DEPARTMENT 

Page 45

TML/MSH Microbiology Department
Policy & Procedure Manual
Policy # MI\TECH\11\v01  Page 4 of 6
Section: Technical Manual  Subject Title: Cryptococcal Antigen 

  6.  Place the slide on the rotator and rotate at 125 rpm for 5 minutes.

  7.  Read the reactions immediately.

 8. Rate the agglutination as follows:
    Positive = any evidence of agglutination (granula tion or clumping)
    Negative = a homogenous suspension  of particles with no  visible clumping.

  9.  Patient specimens showi ng any agglutination in ACGR should  be titrated against
both ACGR and NGR reagents.

    (a)  Prepare two-fold serial dilutions of  the specimen using 200 µL of GBDA in
each of 8 test tubes labelled as follows:

  Tube    1     2       3      4     5         6       7       8

  Serum  1:4   1:8   1:16   1:32   1:64    1:128   1:256 1:512

  CSF    1:2   1:4     1:8   1:16   1:32    1:64    1:128 1:256

    (b)  Transfer one drop of each dilution into 2 rings.
    (c)  Add one drop of ACGR  to one ring of each dilution.
    (d)  Add one drop of NGR  to each of the other rings.
  (e) Mix using separate applicator sticks.
(f)   Place the slide on the rotator and rotate at  125 rpm for 5 minutes.
  (g) Read the results as follows:

      1+ = fine granulation against a milky background
      2+ = small but definite clumps  against a slightly  cloudy background
      3+ = large and small clumps against a clear background
   4+ = large clumps against a clear background

    (h)  If tube #8 gives an agglutination of 2+ or
   greater, the specimen must be further serially
   diluted until a titre may be obtained.

PROCEDURE MANUAL
TORONTO MEDICAL LABORATORIES / MOUNT SINAI HOSPITAL MICROBIOLOGY DEPARTMENT 
 

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