Heat block


Heat block

Heat block is used for incubating sample in test tubes.

Criteria of heat block:

  1.Less expensive to run.
  2.Requires very little maintenance because it is not used.
  3.There is no risk of moisture, entering, tubes are interfering the reaction.

Specification of heat block for district laboratory (Thermolyne heat block):

  1.Heat block may be with a single block or  more than one block temperature of tubes in use.
  2.Thermostatic temperature control that provides stability of the block temperature at± 0.5 °C.
  3.It is supplied with a thermometer which fits the thermometer –drilled holes.

Use and care of heat block:

  1.Check the temperature before using a block.
  2.Use the correct size of diameter tubes in the block.
  3.Clean the block regularly as recommended.
  4.Disconnect the heat block when not using.

 Mixer:

Depending on the type of work performed and workload,

Mixer is 4 types:
1.Roller mixer.
2.Rotator mixer .
3.Vortex mixer.
4.Combined magnetic stirrer and hot plate.

Roller mixer:

Criteria:
 → Easier to use
→Provides gentle but through mixing
→ Can be easily decontaminated of containers.
→Can mix specimen in a variety of containers.

Function of Roller mixer :

It is used particularly for mixing blood specimens and control serum.

Specification of a roller mixer for district laboratory  work:

  1.Five roller capacity.
  2.It provides rotary and tilt mixing of specimens.
  3.Easy to decontaminate and clean.

Rotator mixer:

Function : It is used for controlled mixing of agglutination test (RPR test for syphilis) and other slide or tile agglutination tests performed in the microbiology, hematology and blood transfusion laboratories.

Use and care of mixers:

  1.Read the manufacture’s user manual, prepare a stock record card and written SOPs covering the use card and maintenance of the mixer.
  2.A practical demonstration must be given to the training staff before using a vortex mixer.
  3.Make sure that the containers used on a roller mixer have leak proof caps.
  4.Clean the mixer as recommended by the manufacturer immediately after spillage.
  5.Take special care when using a stirring hot plate use it in a safe place away from flammable chemicals.Tunr it off immediately after use.

Racks and trays:

Criteria: This should be easily disinfected and easily cleaned, such as nylon coated wire or racks made from aluminum polypropylene or other plastic.

Names of different racks:


Tube rack: To hold 12 or more tubes 75 mm long × 10 -13mm diameter.
To hold 12 or mere tubes 100 mm long × 15-20 mm diameter.
To hold 12 or more tubers 125 -150 mm long × 15 -20 mm diameter.

Crossmetch rack:

Preferably for crosshatching  up to 4 units of blood with places for patient, clotted blood sample donor’s red cell suspension tubes and cross match tubes.

EDTA or ESR rack: To hold 12 or 36 EDTA or EST containers up to 5 ml capacity 15-18 mm diameter.

Universal rack:
To hold 12 or more universal or Mc Courtney bottles.

Slide draining rack:
Made by plastic or plaything/ PVC, Block with angled slot to hold 12 or more slides upright for spears to dry after staining.

Drying rack:
Rack for drying washed glassware and plastic ware preferably two sided and free standing with panels. It is polythene coated.

Baskets:
For microbiology work square or round wire baskets are used for autoclaving culture media and specimens.

Trays :
It is used to hold sputum faucal and other specimen containers safely.

Collecting tray:
It is light weight partitioned container with handle, Needed for ward , collection of specimens from patients.