1.5 collection, receipt, storage, management, processing of specimens Flashcards
1.4.1 principles and procedures of washing, sterilisation and care of glassware and other equipment
- use of glassware/what it was used for
- washing manually or using lab glassware washer
- autoclave for sterilisation - esp prior to washing if it has contacted biological material 120deg 30mins
- drying oven
- chromic acid cleaning solution
- new glassware slightly alkaline so needs acid water soak before first use
1.4.2 make up solutions from written formulae
1) desired concentration, usually g/L or if in M, molecular weight of solute (how many g of substance in a mole)
2) required volume
Total solute= volume x concentration (mol/L=M)
1.4.3 Describe three types of microscopes
- upright; light from below, tip of objective point down (usual, fluorescent)
- inverted: light from above, objective beneath stage and point up, for viewing culture petri dishes
- fluorescent: specimen itself emits light, uses mercury lamp as light source to generate fluorescence in the specimen (excitation light)
Describe the necessary steps for maintenance of a microscope according to NATA 1998.
Specifically mention OH&S requirements and details regarding management of mercury lamp
NATA 1998
- not in a highly illuminated room
- spare objectives in disiccator
- adjustable seat
OH&S visual accommodation 30sec every 10 mins
- clean external surfaces only
- daily mx: clean top plate stage/mounting medium, debris
- periodic mx: check quartz halogen globe for corrosion of metal contacts, remove globe 14weekly and polish
- full service q2-3yearly
mercury lamp
- life is 800hours, log on timesheet
- dont turn on/off within 30mins
- breakage or explosion mercury lamp, evaucate, contain an clean PPE* mercury needs to be aspirated using pipette and covered with zinc dust or sulfar powder* safety
1.4.4. aliquot, dilute, store reagents
- keep inventory incl date of prep/expiry
- datasheet for storage antibodies -20, fluorochrome conj ab 8 deg
- storage container- transfer ab to opaque so don’t get quenched
- aliquot first when arrives so prevent contam/freeze thaw cycles
- optimize dilution
1.4.5 calibration, operation and mx of equipment used in assays
Balances
- q3yearly calibration
- check monthly
service 6-12monthly - zero the balance, calibrate using calib weights (standard weights or known volumes of liquid eg water) using forceps- each weight measure 10times for precision
- record mean, median, CV for each
- calculate SD if >0.02 need to contact provider
1.4.5
Pipettes
- can be affected by temp/humidity
- gravimetric analysis
- distilled water dispensed into vessel in precision analytical balance
- eg. 100microL water weigh 100g, 500microl= 500g etc.
- take 10 measurements at each value calculate mean, sd, cv
- can be done by external companies
1.4.5
Timers
- 2x per year
- verified with national institute of standards and technology traceable stopwatch- linked to atomic clock
- calibrate one timer then use it to calibrate others
- calibrated over 60min interval +/- 1 second
Instrument mx principles
- daily start up: waste bottle empty, rinses replinished, prime lines
- daily shut down: flush line,
- weekly/monthly: rinse system etahnol/isopropanol elim debris, rinse with distilled water
- mx log
How to make 1L 5M solution using solute that has molecular weight 75g/mol
conc x volume = total amount of substance required
5M = 75 g x5
Add this amount and make up to 1L (not add 1L)
How do you make a complex solution of 5L of 50nM Nacl, 10mM Tris HCl (C4H11No3)?
a: 5L of 50mM (50mmol/L) Nacl
Total= conc x volume = 250mmol= 0.25mol
molecular mass 58.44g/mol
58.44 x 0.25mol= 7.78h
B: 5L of 10mM of Tris (10mmol/L) conc x vol= 50mmol= 0.05mol molecular mass (off periodic table) 157.56g/mol 157.56g/mol x 0.05mol= 7.78g
so needs 14.61g NacL and 7.78g Tris-Hcl and add solvent to make up total volume of 5L
How do you make 100ml of 0.5M NaCL from stock solution of 5M?
c1v1= c2v2
5mol/L x X = 0.5mol/L x 0.1L
0.01L (10mL) of stock solution add 90mL of solvent to make 100mL
If precious sample is mislabelled?
What are request criteria?
What should be written on the report if accepted?
Requesting criteria
- requester signature
- three identifiers (name, DOB or URN OR address.)
- location to send report
- test requested/samples to take
- identifier on sample match the form
(Blood bank- not accepted)
To accept
- get collector to identify the sample
- someone needs to take responsibility for the sample
Report
- improperly labelled sample did not meet minimum labelling requirements, care should be taken in interpreting result of x
- details of collector identified sample
- recollection should be arranged if possible
List key information required for specimen collection instructions
where should this info be located/in what format
- request form:
- signature
- two identifieers
- tests requested
- label matches forms
- date and time
specimen collection
- tubes
- handling requirements/mix, temp
- transport requirements
- timing
- patient preparation
- collection details /min volume, number of tubes, site of sampling, order of draw
- if non medicare/sign acknowlegement for billing
electronically on intranet, easily accessible
Quick reference guide at sampling centre
What is the difference between plasma and a serum sample?
Plasma contains debris, cellular material and clotting factors ie platelet poor is ideal <10,000 plts
anticogulant (EDTA/citrate/heparinised tube)
If serum is left to clot for longer than 60mins at room temp may hemolyse
