Hazards of Ultraviolet Radiation in Labs

Ultraviolet (UV) radiation is electromagnetic energy with a wavelength just shorter than that of visible light. UV energy stimulates vitamin D production in our bodies and is a treatment for psoriasis, but can also cause skin cancer, sunburns and cataracts. This page will help to identify:

Sources of UV Radiation in Labs

Germicidal lamps emit radiation almost exclusively in the far-UV range of 254 nm. They are commonly used in biological safety cabinets and are not to be relied on as the only method of decontamination.

The UV light box is another UV source in use in laboratories. This instrument is a box with a glass top and a UV lamp inside. Some units have multiple lamps that allow a choice of wavelength.

Most of these instruments are stationary, but a few are hand-held types that carry the same hazards as the stationary models.  Nucleic acid (DNA or RNA) which has been stained with the chemical Ethidium Bromide, lights up when exposed to UV light.

The Journal of Chemical Health & Safety published an assessment of UV exposure from transilluminator light boxes that explains hazards, controls and some common mistakes.

A UV-Crosslinker is used to "cross-link" or covalently attach nucleic acid to a surface or membrane following Southern blotting, Northern blotting, dot blotting, and Colony/Plaque lifts. Since the DNA will be used in place, a 254 nm wavelength is used to maximize adherence.

Teknik Pembuatan Sediaan(preparat) untuk Pemeriksaan Sitologi Dan Pemeriksaan Histologi Di laboratorium Patologi Anatomi.

Patologi Anatomi Adalah spesialis medis yang melakukan diagnosis penyakit berdasarkan pemeriksaan makroskopik, mikroskopik, molekul atas organ, jaringan, dan sel. Yang melakukan diagnosis penyakit berdasarkan patologi anatomi adalah Spesialis patologi anatomi

Spesialis patologi anatomi mendiagnosis penyakit seseorang berdasar pemeriksaan laboratorium. Ada beberapa teknik pemeriksaan di laboratorium patologi anatomi diantaranya pemeriksaan Histologi (morfologi jaringan) atau Sitologi (Morfologi sel). Pada pemeriksaan lab analis kesehatan(teknisi laboratorium) bertugas membuat sediaan/preparat jaringan atau sel yang didapat dari si pasien. Sediaan harus dibuat sebaik mungkin agar spesialis dapat melakukan diagnosis yang akurat.

Produce and Collecting Ascitic Fluid from Mice

Ascitic fluid (also called ascites) is an intraperitoneal fluid extracted from mice that have developed a peritoneal tumor. For antibody production, the tumor is induced by injecting hybridoma cells into the peritoneum, which serves as a growth chamber for the cells. The hybridoma cells grow to high densities and continue to secrete the antibody of interest, thus creating a high-titered solution of antibodies for collection. Antibody concentrations will typically be between 1 and 10mg/ml.

1. Prime adult female mice (at least 6 weeks old) of the same genetic background as your hybridomas by injecting 0.5mL of pristane (2,6,10,14-tetramethyldecanoic acid) into the peritoneum. These solutions will act as irritants to the mice, which respond by secreting nutrients and recruiting monocytes and lymphoid cells into the area. This creates a good environment for the growth of the hybridoma cells.
2. After 7-14 days, inject 5x10(5) to 5x10(6) hybridoma cells ip. Prior to injection, the cells should be growing rapidly. Centrifuge the cells and wash once in PBS. Inject the cells in no more than 0.5mL of PBS.
3. Ascitic fluid may begin to build up within 1-2 weeks following the injection of the cells. Tap the fluid when the mouse is noticeably large, but before the mouse has difficulty moving. Carefully withdraw as much fluid as possible with 18-gauge needle attached to a 5mL syringe.
4. Return the mouse to its cage. Many mice will produce a second or third batch of ascitic fluid. You can also bleed out the mouse and combine the blood with the ascitic fluid.
5. Incubate the fluid at 37°C  for 1 hour. Transfer to 4°C overnight.
6. Spin the fluid at 3000g for 10min. If there is an oil layer, remove this first and discard. Carefully remove the supernatant from the cell pellet. Spin again if necessary.

A single mouse may yield as much as 10mL of ascitic fluid per batch. Antibody concentrations may be as high as 10mg/mL.

Protocol for Real-Time PCR

This protocol describes the detailed experimental procedure for real-time RT-PCR using SYBR Green as was mentioned in Xiaowei Wang and Brian Seed (2003) A PCR primer bank for quantitative gene expression analysis. Nucleic Acids Research 31(24): e154; pp.1-8. Please refer to this paper and the PrimerBank Help page for more background information. The procedure begins with reverse transcription of total RNA. The cDNA is then used as template for real-time PCR with gene specific primers. You may need to modify this protocol if you use different reagents or instruments for real-time PCR.

Time required

	cDNA synthesis: 2 hours.
	real-time PCR: 2 hours.
	Dissociation curve analysis: 0.5 hour.

DNA Precipitation

Overview

This protocol can be used to concentrate DNA, or to change the buffer the DNA is suspended in. It can also be coupled with phenol chloroform extraction for the purifying nucleic acids. This protocol also works for RNA precipitation (take care to use RNAse free materials in this case).

Materials

• 3M NaOAc pH 5.2
• EtOH 95%
• Glycogen (optional)

Induksi mencit : Animal Model invivo pada Diabetes mellitus

Untuk membuat model diabetes mellitus, mencit jantan galur ICR berumur 10 minggu di injeksi tunggal streptozotosin secara intraperitoneal pada dosis 50-150 mg/kg. Kadar glukosa darah diukur secara periodik dengan menggunakan glucose analyzer kit. Vanadil sulfat diberikan secara sub-kutan sekali sehari selama 7 hari pada mencit yang menderita diabetes mellitus. Efektivitas vanadil sulfat dalam menurunkan kadar glukosa darah diukur pada hari 0, 1, 3, 5, 7 dan 14 setelah pemberian.

Pada pemberian streptozotosin dosis rendah (50 mg/kg) dapat menginduksi terjadi diabetes mellitus sebesar 60 % dari populasi mencit. Sementara dengan peningkatan dosis streptozotosin akan meningkatkan prevalensi terjadinya diabetes mellitus. Berdasarkan data penelitian ini dosis yang paling optimal untuk menghasilkan diabetes mellitus tanpa menimbulkan kematian pada mencit adalah 100 mg/kg.

SOP : Fumigation of Laboratory

1.0 OBJECTIVE
To lay down a procedure for Fumigation of Laboratory.

2.0 SCOPE
This SOP is applicable to Quality Control of Laboratory.

3.0 RESPONSIBILITY
Laboratory Technician

4.0 ACCOUNTABILITY
Head of Laboratory.

Comparative Study Methanol Vs Ethanol

Comparative Study Methanol Vs Ethanol

Sr. No.	Parameters	Methanol	Ethanol
1	Systematic name	Methanol	Ethanol
2	Class	Class 2	Class 3
3	Chemical Formula	CH3OH	CH3CH2OH
4	Chemical Structure
5	CAS number	67-56-1	64-17-5
6	PubChem	887	702
7	ChemSpider	864	682
8	UNII	Y4S76JWI15	3K9958V90M
9	EC number	200-659-6	200-578-6
10	UN number	1230	1170
11	KEGG	D02309	D00068
12	MeSH	Methanol	Ethanol
13	ChEBI	CHEBI:17790	CHEBI:16236
14	ChEMBL	CHEMBL14688	CHEMBL545
15	RTECS number	PC1400000	KQ6300000
16	Beilstein Reference	1098229	1718733
17	Gmelin Reference	449	787
18	3DMet	B01170	B01253
19	Molecular formula	CH4O	C2H6O
20	Molar mass	32.04 g mol−1	46.07 g mol−1
21	Physical Appearance	Methanol ‘“is a colorless liquid that is also extremely volatile. Its odor is distinctive and it burns as a bright white flame	Ethanol ‘“is a colorless liquid that is extremely volatile. It has a strong, burning odor and will burn as a bright blue flame.
22	Density	0.7918 g/cm3	0.789 g/cm3 (at 20°C)
23	Melting point	-97.6 °C, 176 K, -144 °F	−114 °C, 159 K, -173 °F
24	Boiling point	64.7 °C, 338 K, 148 °F	78.37 °C, 352 K, 173 °F
25	log P	-0.69	-0.18
26	Vapor pressure	13.02 kPa (at 20 °C)	5.95 kPa (at 20 °C)
27	Acidity (pKa)	15.5	15.9
28	Refractive index (nD)	1.33141	1.361
29	Viscosity	5.9×10−4 Pa s (at 20 °C)	0.0012 Pa s (at 20 °C), 0.001074 Pa s (at 25 °C)
30	Dipole moment	1.69 D	1.69 D
31	European Union classification	F T	F
32	Flash point	11–12 °C	13–14 °C
33	Concentration limit in Extract	3000 ppm	5000 ppm
34	Auto ignition temperature	385 °C	363 °C