Quarterly report pursuant to Section 13 or 15(d)

5. Property and Equipment, net (Details)

v2.4.1.9
5. Property and Equipment, net (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Property, Plant and Equipment [Line Items]    
Property and equipment - at cost $ 336,444us-gaap_PropertyPlantAndEquipmentGross $ 586,113us-gaap_PropertyPlantAndEquipmentGross
Less accumulated depreciation (246,741)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment (466,664)us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Property and equipment - net 89,703us-gaap_PropertyPlantAndEquipmentNet 119,449us-gaap_PropertyPlantAndEquipmentNet
Laboratory Equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property and equipment - at cost 254,150us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= xbio_LaboratoryEquipmentMember
254,150us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= xbio_LaboratoryEquipmentMember
Office and Computer Equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property and equipment - at cost 35,190us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= xbio_OfficeAndComputerEquipmentMember
189,459us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= xbio_OfficeAndComputerEquipmentMember
Leasehold Improvements [Member]    
Property, Plant and Equipment [Line Items]    
Property and equipment - at cost 26,841us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
92,354us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LeaseholdImprovementsMember
Furniture and Fixtures [Member]    
Property, Plant and Equipment [Line Items]    
Property and equipment - at cost $ 20,263us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_FurnitureAndFixturesMember
$ 50,150us-gaap_PropertyPlantAndEquipmentGross
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_FurnitureAndFixturesMember