Instruments in pathology .pptx

Pathology instruments for 2nd MBBS students

1. Specimens and Instruments Department of pathology Andhra Medical College

2. List of instruments Wintrobe’s tube Wstergren’s pipette RBC pipette WBC pipette Hemoglobinometer Neubaur chamber LP Needle Bone marrow aspiration needle Liver biopsy needle Urinometer Graduated conical centrifuge tube Tissue cassette Paraffin wax block L- mould

3. WBC PIPETTE This is a bulb pipette having a long stem with a capillary bore and a pointed tip. The bulb contains a white bead inside. A small rubber tube provided with a mouth piece is connected to the small narrow portion, above the bulb for sucking blood and fluid into the pipette. The pipette has three markings on in it, 0.5 mark in the middle of the stem, 1 mark at the junction between stem and bulb, and 11 mark above the bulb.

4. WBC PIPETTE The total volume of the pipette is 11 parts, of which one part is in the stem and 10 parts in the bulb. The column of diluting fluid contained in the stem of the pipette does not enter into the dilution (i.e. 11-1 = 10), so that the blood sucked upto 0.5 mark will have a dilution of 0.5 in 10 or 1 in 20. Other uses of WBC pipette: 1. Cell count in C.S.F. 2. Sperm count 3. Absolute Eosnophil count 4. R.B.C. count in severe anaemia

5. RBC PIPETTE  This is a bulb pipette having a long stem with a capillary bore and a pointed tip. The bulb contains a red bead inside. A small rubber tube provided with a mouth piece is connected to the small narrow portion above the bulb for sucking blood and fluid into the pipette. The pipette has three markings on in it, 0.5 mark in the middle of the stem, 1 mark at the junction between stem and bulb, and 101 mark above the bulb. The total volume of the pipette is 101 parts, of which one part is in the stem and 100 parts in the bulb.

6. RBC PIPETTE  Other uses of R.B.C. pipette: 1. WBC count in leukemias 2. Platelet counting Uses of the bead in the bulb 1. For proper mixing 2. To know whether the pipette is dry 3. To identify the pipette R.B.C diluting fluid: Hayem’s fluid is the commonly used diluting fluid.

7. IMPROVED NEUBAUR CHAMBER This is a thick rectanguar glass with a polished transverse bar in the centre , separated from the rest of the slide by two parallel grooves on either side. The polished bar is divided into two equal platforms by a groove in the middle resulting in ‘H’ shaped depression (moats). The surface of the platforms is 1/10 mm below the surface of the rest of the slide. So if a cover glass is placed over the surface of the counting chamber, the under surface of the coverglass remains 1/10 mm above the polished surface of the platform.

8. ESBACH’S ALBUMINOMETER This is a glass tube with markings. Two markings are seen : U & R : U- Urine, R- Reagent Uses: 1. Quantitative estimation of protein(albumin) in urine.

9. HEMOGLOBINOMETER Description : This device holds mainly 4 parts : Stirer : Thin rod glass Haemoglobin pipette Sahli’s graduated haemoglobin tube Comparator with a brown glass standard Uses : To measure Haemoglobin concentration in the blood.

10. SAHLI HEMOGLOBINOMETER Advantages : Simple method Small quantity of blood is needed Can be easily repeated Disadvantages : Operator visual error Other forms of Hb cannot be estimated Fading of standard – false reading Affected by hyperbilirubinemia

11. HEMOGLOBIN PIPETTE Description : white tube without bulb Component of Sahli’s hemoglobinometer Uses : To measure Haemoglobin concentration in the blood.

12. WINTROBE’S TUBE or HEMATOCRIT TUBE Thick walled tube with narrow lumen, one end closed. Total length – 11 cm, diameter 2.5 cm Graduated – 0-100 mm It has two measurements – one for PCV one for ESR Below upward markings – PCV Above downward marking – ESR Anticoagulant used – double oxalate, dry ammonium oxalate mixture

13. WINTROBE’S TUBE or HEMATOCRIT TUBE After centrifugation forms 3 layers : Plasma layer Buffy coat – WBC and Platelets Packed RBC’S ( Haematocrit ) Uses : Determination of : ESR PCV Buffy coat smear preparation

14. URINOMETER Parts – weighed glass cylinder, bulb containing mercury and stem. The stem has scale with readings 1.000 to 1.060 with divisions of 0.001- 0.002 used at temp of 15 C Uses : To measure specific gravity of urine.

15. URINOMETER Based on principle of Bouyancy . Due to increased density of urine as compared to water, urinometer will float higher in urine than in water. The weighted float will displace the volume of urine equal to its weight.

16. WESTERGREN’S PIPETTE 30 cm long tube open at both ends. Diamete 2.5 cm Markings – 0-200 mm Anticoagulant used – Trisodium citrate (3.8%) – 0.4ml with 1.6ml venous blood Uses : Used for measurement of ESR.

17. WESTERGREN’S PIPETTE Precautions Tube should be grease free Vertically placed No vibrations Not be exposed to direct sunlight/ heat Causes of raised ESR Tuberculosis, infections, cancer Chronic diseases – arthritis, ankylosing spondylitis etc.

18. SALAH BONE MARROW ASPIRATION NEEDLE Shorter needle Parts - wide bore needle, stylet and guard Sites of bone marrow aspiration: Posterior iliac crest Anterior superior iliac crest Sternum (last resort in morbid obese and older than 12 years) Tibia (Only in infants younger than 1 years)

19. INDICATIONS OF BONE MARROW ASPIRATION Unexplained anaemia , abnormal red cell indices, cytopenias or cytoses Abnormal peripheral blood smear morphology suggestive of bone marrow pathology Diagnosis, staging and follow-up of malignant haematological disorders (e.g. acute and chronic leukaemias,myelodysplastic syndromes, chronic myeloproliferative disorders, lymphomas, plasma cell myeloma, amyloidosis, mastocytosis ) Suspected bone marrow metastases Unexplained focal bony lesions on radiological imaging Unexplained organomegaly or presence of mass lesions inaccessible for biopsy Microbiological culture for investigations of pyrexia of unknown origin or specific infections, e.g. military tuberculosis, leishmaniasis, malaria Evaluation of iron stores Investigation of lipid/glycogen storage disorders Exclusion of haematological disease in potential allogeneic stem cell transplant donors

20. BONE MARROW BIOPSY NEEDLE - Jamshidi Needle Longer can be used for both aspiration & biopsy from iliac crest. Parts – wide bore needle, stylet and hook Uses : To take bone marrow biopsy sample

21. LUMBAR PUNCTURE NEEDLE Thin needle used to puncture lumbar areaL3-L4 or L4-L5 interspace. Uses : Collect CSF sample (spinal tap) for biochemical, microbiological and cytological analysis Aspiration from peritoneal cavity, pleural, joint space. Spinal anesthesia Therapeutic lumbar puncture (to relieve increased ICP)

22. VIM-SILVERMAN (LIVER BIOPSY NEEDLE) The needle consists of 3 parts Trocar, Cannula, Bifid needle Indications of liver biopsy Cirrhosis of liver Malignancy Granuloma Metabolic and storage disorders Unexplained jaundice

23. VIM-SILVERMAN (LIVER BIOPSY NEEDLE) Contraindications of liver biopsy Bleeding disorders Infections in liver, peritoneum, biliary tract Hydatid cyst Hemangioma Chronic passive congestion of liver

24. VIM-SILVERMAN (LIVER BIOPSY NEEDLE) Complications of liver biopsy Puncture of gall bladder – bile leakage – biliary peritonitis Hemorrhage Cholangitis Puncture of viscera – Kidney or colon, pancreas

25. GRADUATED CONICAL CENTRIFUGE TUBE

26. CASETTE Instrument name: Tissue cassettes Use: Tissue processing – these cassettes are totally resistant to most reagents and their slots offer maximum flow through for good fluid exchange and proper drainage

27. L - MOULD Use: Tissue embedding – tissue is embedded to make tissue block used to prepare paraffin blocks

28. PARAFFIN WAX BLOCK Use:  Tissue embedding – After adding fixative, biopsies are embedded in paraffin/wax to support the tissue so that thin sections or slices can be cut and placed on a microscope slide.

29. PASTEUR’S PIPETTE